Roof panel and building provided with said roof panel

Abstract

A roof panel is installed across and on an upper side of a plurality of horizontal members that extend in a roof lateral direction and arranged at intervals in a roof longitudinal direction orthogonal to the roof lateral direction. The roof panel includes: a frame body disposed across the plurality of horizontal members in an installed state of the roof panel; an upper heat insulation layer and a lower heat insulation layer that are supported by the frame body and are disposed side by side, one above the other; and a roof side airtight layer interposed between the upper heat insulation layer and the lower heat insulation layer, in which a thickness of the upper heat insulation layer is larger than a thickness of the lower heat insulation layer.

Description

DESCRIPTIONTechnical Field

[0001] The present invention relates to a roof panel and a building provided with the roof panel.Background Art

[0002] Conventionally, there has been known a roof panel including a roof frame, a heat insulation member disposed in a space in the roof frame, and an airtight moisture-proof sheet covering the heat insulation member on a lower surface of the roof frame (see, for example, Patent Literature 1 below).

[0003] The roof panel is installed across and on an upper side of a plurality of horizontal members extending in a roof lateral direction (a width direction of the roof), such as a ridge beam, a purlin, and an eaves beam. The roof frame used for the roof panel includes a plurality of rafter members extending in a direction orthogonal to the horizontal member and disposed at intervals in the roof lateral direction. Spaces between the plurality of rafter members are filled with the heat insulation member. A lower surface of the heat insulation member is covered with the moisture-proof sheet. A roof board is fixed to an upper surface of the heat insulation member, and a finishing material is fixed to a lower surface of the moisture-proof sheet.CITATION LISTPatent LiteraturePatent Literature 1: JP 2019-90224 ASUMMARY OF INVENTIONProblems to be Solved by the Invention

[0005] In the conventional roof panel disclosed in Patent Literature 1, a lower surface of the heat insulation member (heat insulation layer) is covered with the moisture-proof sheet (roof side airtight layer). For this reason, in winter, entry of high-humidity air in a building into the heat insulation layer is suppressed by the roof side airtight layer, and as a result, dew condensation (so-called winter type dew condensation) in the heat insulation layer is suppressed. However, in summer, high-humidity air outside the building passes through the heat insulation layer of the roof panel and reaches the roof side airtight layer, and in this state, the roof side airtight layer is cooled by the air cooled by an air conditioner, so that dew condensation (so-called summer type dew condensation) occurs in the heat insulation layer. As described above, in the conventional roof panel, although the generation of the winter type dew condensation in the heat insulation layer can be suppressed, the generation of the summer type dew condensation cannot be suppressed. Therefore, it is conceivable to dispose the roof side airtight layer on the upper surface of the heat insulation layer in order to suppress the summer type dew condensation, but in this case, since the roof side airtight layer is cooled by low-temperature outside air in winter, the winter type dew condensation occurs in the heat insulation layer as described above. When dew condensation occurs in the heat insulation layer regardless of whether it is summer type dew condensation or winter type dew condensation, corrosion of the heat insulation layer proceeds to cause a problem that heat insulation performance of the heat insulation layer is deteriorated.

[0006] An object of the present invention is to effectively suppress occurrence of dew condensation in a heat insulation layer of a roof panel regardless of summer type dew condensation and winter type dew condensation.Means for Solving the Problems

[0007] A roof panel according to one aspect of the present invention is a roof panel installed across and on an upper side of a plurality of horizontal members, the plurality of horizontal members extending in a roof lateral direction and arranged at intervals in a roof longitudinal direction orthogonal to the roof lateral direction, the roof panel including: a frame body disposed across the plurality of horizontal members in an installed state of the roof panel; an upper heat insulation layer and a lower heat insulation layer that are supported by the frame body and are disposed side by side, one above another; and a roof side airtight layer interposed between the upper heat insulation layer and the lower heat insulation layer, in which a thickness of the upper heat insulation layer is larger than a thickness of the lower heat insulation layer.BRIEF DESCRIPTION OF DRAWINGS

[0008] FIG. 1 is a vertical cross-sectional view along a roof longitudinal direction illustrating a vicinity of a roof of a building provided with a roof panel according to an embodiment of the present invention.

[0009] FIG. 2 is a perspective view illustrating an inclined roof portion.

[0010] FIG. 3 is an enlarged cross-sectional view illustrating a portion III in FIG. 1 in an enlarged manner.

[0011] FIG. 4 is a vertical cross-sectional view along the roof longitudinal direction illustrating a state immediately before the roof panel is installed on an upper side of a plurality of horizontal members provided in a building body.

[0012] FIG. 5 is an internal cut model in which a part of the roof panel is cut and each layer inside the roof panel is exposed in order from an upper layer.

[0013] FIG. 6 is a perspective view illustrating an extracted frame body of the roof panel.

[0014] FIG. 7 is an extracted perspective view illustrating a frame body, a roof side moisture-proof sheet, and an eaves beam attachment member in the roof panel.

[0015] FIG. 8 is a perspective view illustrating a state in which a purlin attachment member is further attached to the frame body from the state of FIG. 7.

[0016] FIG. 9 is a perspective view illustrating a state in which a lower heat insulation member is further attached to the frame body from the state of FIG. 8.

[0017] FIG. 10 is a perspective view illustrating a state in which an upper heat insulation member is further attached to the frame body from the state of FIG. 9.

[0018] FIG. 11 is a completed perspective view illustrating a state in which a roof board is further attached to the frame body from the state of FIG. 10.

[0019] FIG. 12A is a view corresponding to a partial cross-sectional view of a left end of FIG. 4 and illustrating a first modified embodiment.

[0020] FIG. 12B is a view corresponding to a partial cross-sectional view of a left end of FIG. 4 and illustrating a second modified embodiment.

[0021] FIG. 13A is a view corresponding to a partial cross-sectional view of a left end of FIG. 4 and illustrating a third modified embodiment.

[0022] FIG. 13B is a view corresponding to a partial cross-sectional view of a left end of FIG. 4 and illustrating a fourth modified embodiment.DESCRIPTION OF EMBODIMENTS

[0023] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view illustrating the vicinity of a roof of a building 1 including a roof panel 100 according to an embodiment of the present invention. Note that, although a vertical direction and a left and right direction (horizontal direction) are illustrated in FIG. 1, the direction is illustrated to describe the roof panel 100 according to the present embodiment and the building 1 including the same, and does not limit the structure, the use mode, and the like of the roof panel and the building according to the present invention. Furthermore, in FIG. 1, as an example, the left side of the plane of drawing is illustrated as the outside of the building 1, and the right side of the plane of drawing is illustrated as the inside of the building 1.Overall Configuration of Building

[0024] The building 1 includes a building body 10 and a roof 50 constituted by a plurality of roof panels 100.

[0025] The roof 50 is disposed so as to close the ceiling side of the building body 10 and partitions an outdoor space OS and an indoor space IS. The roof 50 is a so-called gable roof, and has a pair of left and right inclined roof portions 50L and 50R arranged so as to constitute a hypotenuse of an isosceles triangle having a ridge as a vertex when viewed from the end side (front side in a direction perpendicular to the plane of FIG. 1). In FIG. 1, only the left inclined roof portion 50L and the vicinity of the periphery thereof and the vicinity of the upper end portion of the other inclined roof portion 50R are illustrated, and the other portions are omitted. Note that, in the following description, a direction parallel to the ridge of the roof 50 (a direction perpendicular to the plane of FIG. 1) is defined as a roof lateral direction, and a direction orthogonal to the roof lateral direction along the roof surface (in this example, the same direction as a roof inclination direction) is defined as a roof longitudinal direction.

[0026] FIG. 2 is a perspective view illustrating the inclined roof portions 50L and 50R constituting the roof 50. Each of the inclined roof portions 50L and 50R includes a plurality of roof panels 100 arranged in the roof lateral direction. Each roof panel 100 is installed across and on an upper side of a plurality of horizontal members 21 provided on the building body 10. Note that, in FIG. 2, only two roof panels 100 located at both ends in the roof lateral direction are illustrated, and the roof panel 100 located between the two roof panels is not illustrated.

[0027] Referring to FIG. 1, a plurality of tile bars 52 extending in a roof lateral direction (a direction perpendicular to the plane of FIG. 1) and arranged at intervals in a roof longitudinal direction are fixed to an upper surface of each roof panel 100 (an upper surface of a roof board 160 to be described later), and a tile 51 is laid across the adjacent tile bars 52. The upper end portion of each tile 51 is latched to the tile bar 52, and the lower end portion is overlapped and fixed to the upper end portion of the tile 51 adjacent on the lower side from above.Building Body

[0028] The building body 10 includes a roof support structure 20 including the plurality of horizontal members 21 and a side wall portion 30 forming a side surface of the building 1.

[0029] The roof support structure 20 includes a ridge beam 22, a purlin 23, and an eaves beam 24 as the horizontal members 21. The ridge beam 22, the purlin 23, and the eaves beam 24 are made of a wooden long member having a rectangular cross section extending in the roof lateral direction, and are arranged at intervals in the roof longitudinal direction. The ridge beam 22, the purlin 23, and the eaves beam 24 are arranged such that the installation height decreases in this order from the ridge side to the eaves side according to a roof gradient. The eaves beam 24 corresponds to an outermost horizontal member located on the most roof outer side in the roof longitudinal direction. Note that the arrangement of the horizontal members 21 in FIG. 1 is an example, and the number and shape of the horizontal members 21 are not limited thereto. Furthermore, the material of the horizontal member 21 is not limited to wood, and may be, for example, metal.

[0030] Only one ridge beam 22 is provided below the boundary portion between the left and right inclined roof portions 50L and 50R. The purlin 23 and the eaves beam 24 are provided below the left and right inclined roof portions 50L and 50R, respectively. A plurality of the purlins 23 may be provided. A beam 28 located at the same height as the two eaves beams 24 and extending in the roof lateral direction is disposed at the center between the left and right eaves beams 24.

[0031] The left and right eaves beams 24 and the central beam 28 are coupled by a plurality of joists (not illustrated) extending in the left and right direction and arranged at intervals in the roof lateral direction.

[0032] The ridge beam 22 and the purlin 23 are connected to the plurality of beams via a hut bundle (not illustrated). The eaves beam 24 is supported from below by a plurality of pillar members 38 (only one is illustrated in FIG. 1) extending in the vertical direction and arranged at intervals in a roof lateral direction (a direction perpendicular to the plane of FIG. 1). The plurality of pillar members 38 function as a support member of the eaves beam 24 and also function as a framework member of the side wall portion 30 described later.

[0033] As illustrated in FIG. 3, the side wall portion 30 is a vertical wall portion whose upper end portion is connected to the roof 50, and is disposed so as to partition the outdoor space OS and the indoor space IS.

[0034] Specifically, the side wall portion 30 includes an outer wall panel 31, an outer heat insulation layer 32, a base material 33, an inner heat insulation layer 34, a body side moisture-proof sheet 35 as a body side airtight layer 39, and an inner wall panel 36, which are disposed in this order from the outside to the inside in the wall thickness direction.

[0035] The outer wall panel 31 is a member that forms an outer wall surface of the building 1, and extends along the vertical direction. The outer wall panel 31 is disposed at a position slightly spaced apart outward from the outer heat insulation layer 32, and forms a wall side ventilation passage 37 extending in the vertical direction between the outer wall panel and the outer heat insulation layer 32.

[0036] The outer heat insulation layer 32 faces the wall side ventilation passage and is disposed inside the wall side ventilation passage 37. The outer heat insulation layer 32 can enhance heat insulation properties between the outdoor space OS and the indoor space IS. The outer heat insulation layer 32 is made of a hard heat insulation material such as extruded expanded polystyrene. However, the outer heat insulation layer 32 may be made of a fibrous heat insulation material such as cellulose fiber, rock wool, or glass wool.

[0037] The base material 33 is disposed inside the outer wall panel 31 and is made of, for example, plywood. The base material 33 is disposed so as to cover the outer side surface of the eaves beam 24, the outer side surfaces of the plurality of pillar members 38 (only one is illustrated in FIG. 3) supporting the eaves beam 24, and the space S0 between the plurality of pillar members 38 from the outside. Here, the outer side surfaces of the plurality of pillar members 38 and the outer side surface of the eaves beam 24 are flush with each other with a joint therebetween to form an attachment surface of the base material 33. The base material 33 is fixed to the attachment surface with a nail or the like.

[0038] The inner heat insulation layer 34 is a heat insulation material disposed inside the outer heat insulation layer 32, and has a function of enhancing heat insulation properties between the outdoor space OS and the indoor space IS similarly to the outer heat insulation layer 32. The inner heat insulation layer 34 is made of a heat insulation material filled in a space S0 formed between the plurality of pillar members 38 on the lower side of the eaves beam 24, and is made of a fiber-type heat insulation material such as cellulose fiber, rock wool, or glass wool. However, the inner heat insulation layer 34 may be made of a hard heat insulation material such as extruded expanded polystyrene.

[0039] The body side moisture-proof sheet 35 as the body side airtight layer 39 is formed of one or a plurality of resin sheets. The body side moisture-proof sheet 35 is disposed along the vertical direction, and is disposed to cover the inner side surfaces of the plurality of pillar members 38, the inner side surface of the eaves beam 24, and the space S0 between the plurality of pillar members 38 from the inside. The height position of the upper end surface of the body side moisture-proof sheet 35 coincides with the height position of the upper surface of the eaves beam 24. In other words, the upper end surface of the body side moisture-proof sheet 35 is flush with the upper surface of the eaves beam 24. Here, the inner side surfaces of the plurality of pillar members 38 and the inner side surface of the eaves beam 24 are flush with each other with a joint therebetween to form an attachment surface of the body side moisture-proof sheet 35. The body side moisture-proof sheet 35 is fixed to the attachment surface with staples or the like. Thus, the body side moisture-proof sheet 35 can enhance airtightness and moisture-proof properties between the outdoor space OS and the indoor space IS in the side wall portion 30 of the building body 10.

[0040] Note that, in the present embodiment, the eaves beam 24 is made of wood as an example, but even if the eaves beam 24 is made of wood depending on the required airtightness level, the eaves beam 24 itself forms an airtight line (see FIG. 1; details are described below). In this case, the upper end surface of the body side moisture-proof sheet 35 may be located at a height between the upper surface and the lower surface of the eaves beam 24 or at the same height as the lower surface of the eaves beam 24. According to this, the eaves beam 24 itself constitutes a part of the airtight line K, and the body side moisture-proof sheet 35 and a roof side moisture-proof sheet 141 to be described later are connected by the eaves beam 24, whereby the airtight line K (see FIG. 1) extending from the building body 10 side to the roof 50 side is formed.

[0041] The inner wall panel 36 is made of a plate material such as plasterboard, for example, and is disposed such that its inner surface faces an interior space S1. The inner wall panel 36 is disposed inside the body side moisture-proof sheet 35 along the vertical direction.

[0042] An upper end surface of the inner wall panel 36 is connected to a lower surface of a ceiling plate member 25 that partitions the interior space S1 and the attic space S2. The ceiling plate member 25 is supported by a field edge 26 extending in the left and right direction at the lower end of the roof support structure 20 described above. Both end portions of the field edge 26 in the left and right direction are coupled to the inner side surface of the eaves beam 24 via a base tree 40 and a coupling plate member 41.Roof Panel

[0043] Next, details of the roof panel 100 constituting the roof 50 will be described. FIG. 4 is a vertical cross-sectional view taken along the roof longitudinal direction illustrating a state immediately before the roof panel 100 is installed on the upper side of the ridge beam 22, the purlin 23, and the eaves beam 24. As illustrated in this drawing, the roof panel 100 is installed from above at a predetermined installation position above the ridge beam 22, the purlin 23 and the eaves beam 24. As described later, the roof panel 100 is completely installed by fixing an eaves beam attachment member 151 to the upper surface of the eaves beam 24 and fixing a purlin attachment member 150 to the upper surface of the purlin 23. In the following description, unless otherwise specified, the roof panel 100 will be described assuming that the installation of the roof panel 100 is completed (hereinafter, referred to as an installed state).

[0044] FIG. 5 is an internal cut model in which a part of the roof panel 100 is cut to expose each layer 120, 130, 140 inside in order from the upper layer.

[0045] The roof panel 100 includes a frame body 110, a plurality of upper heat insulation members 121 constituting the upper heat insulation layer 120, a plurality of lower heat insulation members 131 constituting the lower heat insulation layer 130, one roof side moisture-proof sheet 141 constituting the roof side airtight layer 140, a purlin attachment member 150, an eaves beam attachment member 151, and a plurality of roof boards 160.

[0046] FIG. 6 is an extracted perspective view illustrating the frame body 110 of the roof panel 100. Referring to FIGS. 5 and 6, the frame body 110 includes a plurality of (four in this example) rafter members 111 extending in the roof longitudinal direction across the ridge beam 22, the purlin 23, and the eaves beam 24 in the installed state of the roof panel 100, and a coupling member 112 coupling the plurality of rafter members 111. The frame body 110 is made of wood, but is not limited thereto, and may be made of metal or resin, for example.

[0047] The plurality of rafter members 111 are disposed at intervals (at equal intervals in the example of FIG. 6) in the roof lateral direction. Each of the rafter members 111 is formed of a long plate member extending in the roof longitudinal direction and having a thickness in the roof lateral direction.

[0048] The coupling member 112 is formed of a long plate member extending in the roof lateral direction. The coupling member 112 is fixed to each of the plurality of rafter members 111 in a state where one side surface in the thickness direction abuts on eaves side end surfaces of the plurality of rafter members 111. The coupling member 112 includes a coupling body 112a extending from the rafter member 111 located at the most one-side end in the roof lateral direction to the rafter member 111 located at the most other-side end, and a protruding plate 112b connected to the coupling body 112a and protruding toward the other side from the rafter member 111 located at the most other-side end. A protruding length L2 of the protruding plate 112b is set to be equal to, for example, an interval L1 between the adjacent rafter members 111. By providing the protruding plates 112b in this manner, when the frame bodies 110 are disposed in the roof lateral direction, the rafter members 111 of the adjacent frame bodies 110 are disposed so as to compensate for the rafter members 111 missing at the protruding end portions of the protruding plates 112b. Therefore, it is possible to prevent the rafter members 111 from being disposed in an overlapping manner (one extra member is arranged) near the boundary portions of the frame bodies 110 adjacent to each other.

[0049] Furthermore, a communication passage 162 (see FIGS. 1 and 3) which is a space partitioned by the plurality of rafter members 111 and communicating with a roof side ventilation passage 161 to be described later is formed between the coupling member 112 and the eaves side end surface of the upper heat insulation layer 120.

[0050] FIG. 7 is an extracted perspective view illustrating the frame body 110, the roof side moisture-proof sheet 141, and the eaves beam attachment member 151 of the roof panel 100. As illustrated in FIGS. 4 and 7 described above, the roof side moisture-proof sheet 141 is made of, for example, one resin sheet.

[0051] As illustrated in FIG. 4, the roof side moisture-proof sheet 141 has a flat sheet portion 141a and a lower extending sheet portion 141b. The flat sheet portion 141a corresponds to an intervening portion interposed between the upper heat insulation layer 120 and the lower heat insulation layer 130, and the lower extending sheet portion 141b corresponds to a non-intervening portion connected to the intervening portion.

[0052] The flat sheet portion 141a has a rectangular sheet shape having the same width as the coupling member 112 of the frame body 110. The flat sheet portion 141a is formed across the ridge beam 22 and the eaves beam 24 when viewed from a direction perpendicular to the roof surface so as to close a space therebetween. As illustrated in FIG. 7, the flat sheet portion 141a is disposed along lower end surfaces of the plurality of rafter members 111 in the frame body 110, and is fixed to the frame body 110 by staples (not illustrated).

[0053] The lower extending sheet portion 141b is connected to an eaves side end edge of the flat sheet portion 141a. The lower extending sheet portion 141b extends downward (vertically lower side in this example) from an extension line of the flat sheet portion 141a. As illustrated in FIG. 4, the lower extending sheet portion 141b extends vertically downward from the eaves side end edge of the flat sheet portion 141a while being sandwiched between the eaves beam attachment member 151 and the lower heat insulation member 131. The lower end surface of the lower extending sheet portion 141b is located at the same height as a lower surface 151c of the eaves beam attachment member 151. In other words, the lower end surface of the lower extending sheet portion 141b is formed to be flush with the lower surface 151c of the eaves beam attachment member 151. Furthermore, the lower end surface placement of the lower extending sheet portion 141b is located slightly lower than the lower end position of the adjacent lower heat insulation member 131. The lower end surface of the lower extending sheet portion 141b abuts on the upper end surface of the body side moisture-proof sheet 35 in the installed state of the roof panel 100 (see FIG. 3). Note that the lower extending sheet portion 141b may be disposed so as to overlap the body side moisture-proof sheet 35 in the thickness direction.

[0054] The eaves beam attachment member 151 is a member for attaching the roof panel 100 to the upper surface of the eaves beam 24. As illustrated in FIG. 7, the eaves beam attachment member 151 is fixed to a place corresponding to the eaves beam 24 on the lower end surface of each of the rafter members 111 by a screw 101. The eaves beam attachment member 151 extends in a direction orthogonal to each of the rafter members 111 when viewed from below.

[0055] Specifically, the eaves beam attachment member 151 is formed of a long member having a triangular prism shape extending in the roof lateral direction. The length of the eaves beam attachment member 151 in the roof lateral direction is set to be equal to the lateral width of the roof side moisture-proof sheet 141, for example.

[0056] As illustrated in FIG. 4, the eaves beam attachment member 151 is disposed facing (adjacent to) the lower extending sheet portion 141b of the roof side moisture-proof sheet 141 in the roof longitudinal direction. The eaves beam attachment member 151 is interposed between the eaves beam 24 and the frame body 110 to hold an inclination angle of each of the rafter members 111 with respect to the horizontal direction (the left and right direction in this example) at a predetermined angle (an angle corresponding to a roof gradient).

[0057] Specifically, the eaves beam attachment member 151 includes: an inclined surface 151a that is inclined so as to be lower from the ridge side toward the eaves side at an angle according to the roof gradient; a vertical end surface 151b that extends downward from an upper end edge of the inclined surface 151a; and a horizontal lower surface 151c that connects a lower end edge of the vertical end surface 151b and a lower end edge of the inclined surface 151a. The inclined surface 151a of the eaves beam attachment member 151 is in contact with the lower end surface of each of the rafter members 111. The lower surface 151c of the eaves beam attachment member 151 is placed on an upper surface of the eaves beam 24. The vertical end surface 151b sandwiches the lower extending sheet portion 141b of the roof side moisture-proof sheet 141 with the lower heat insulation member 131 to fix the lower extending sheet portion 141b.

[0058] FIG. 8 is a perspective view illustrating a state in which the purlin attachment member 150 is further attached to the frame body 110 from the state of FIG. 7. The purlin attachment member 150 is a member for attaching the roof panel 100 to the purlin 23 (see FIG. 4).

[0059] Referring to FIGS. 4 and 8 described above, the purlin attachment member 150 is fixed at a position corresponding to the purlin 23 on the lower end surface of each of the rafter members 111 with the roof side moisture-proof sheet 141 interposed therebetween. For this fixing, for example, a screw 102 (see FIG. 8) is used. The purlin attachment member 150 extends in a direction orthogonal to each of the rafter members 111 when viewed from below.

[0060] The purlin attachment member 150 is interposed between the purlin 23 and the frame body110 to hold an inclination angle of each of the rafter members 111 with respect to the horizontal direction (the left and right direction in this example) at the predetermined angle (an angle corresponding to a roof gradient). A basic configuration of the purlin attachment member 150 is similar to that of the eaves beam attachment member 151. That is, the purlin attachment member 150 includes an inclined surface 150a, a vertical end surface 150b, and a lower surface 150c, the inclined surface 150a abuts on the lower end surface of each of the rafter members 111, and the lower surface 150c is placed on the upper surface of the purlin 23. The vertical end surface 150b abuts on the end face of the lower heat insulation member 131 located on the ridge side to position the lower heat insulation member 131 in the roof longitudinal direction.

[0061] FIG. 9 is a perspective view illustrating a state where the lower heat insulation member 131 is further attached to the frame body 110 from the state of FIG. 8.

[0062] As illustrated in FIGS. 4 and 9, the lower heat insulation member 131 has a rectangular plate shape elongated in the roof longitudinal direction. In the present embodiment, four lower heat insulation members 131 are provided in total, and each of the lower heat insulation members 131 is made of a hard heat insulation material such as extruded expanded polystyrene. However, each lower heat insulation member 131 may be made of a fibrous heat insulation material such as cellulose fiber, rock wool, or glass wool. The four lower heat insulation members 131 are fixed to the frame body 110 with the roof side moisture-proof sheet 141 interposed therebetween. Two lower heat insulation members 131 are provided in each of an eaves side region r1 between the eaves beam attachment member 151 and the purlin attachment member 150 on the lower surface side of the frame body 110 and a ridge side region r2 on the ridge side with respect to the purlin attachment member 150 on the lower surface side of the frame body 110. The eaves side region r1 corresponds to a space between the purlin 23 and the eaves beam 24, and the ridge side region r2 corresponds to a space between the ridge beam 22 and the purlin 23. In each of the regions r1 and r2, the two lower heat insulation members 131 are disposed side by side without a gap in the roof lateral direction. Each lower heat insulation member 131 is fixed to the frame body 110 with the flat sheet portion 141a of the roof side moisture-proof sheet 141 interposed therebetween. For this fixing, for example, a screw 103 is used. The four lower heat insulation members 131 constitute the lower heat insulation layer 130. The lower heat insulation layer 130 has a function of enhancing heat insulation properties between the outdoor space OS and the indoor space IS in the roof 50 (see FIGS. 1 and 3).

[0063] As illustrated in FIG. 4, the lower heat insulation member 131 disposed on the ridge side is disposed so as to expose the ridge side end edge of the flat sheet portion 141a of the roof side moisture-proof sheet 141. This exposed portion constitutes a ridge attachment surface portion 141c for attaching the roof panel 100 to the ridge beam 22. A pedestal member 27 to which the ridge attachment surface portion 141c is fixed is provided on the upper surface of the ridge beam 22. The pedestal member 27 is an elongated member having a substantially trapezoidal cross section and extending over the entire ridge beam 22 in the extending direction, and includes left and right inclined surfaces 27a inclined along the roof gradient, a horizontal upper end surface 27b connecting upper ends of the left and right inclined surfaces 27a, and a lower surface 27c fixed to an upper surface of the ridge beam 22. The left and right inclined surfaces 27a and the horizontal upper end surface 27b are covered with a ridge beam moisture-proof sheet 29. The ridge beam moisture-proof sheet 29 is made of one resin sheet, and is fixed to the left and right inclined surfaces 27a and the horizontal upper end surface 27b of the pedestal member 27 with an adhesive or the like.

[0064] FIG. 10 is a perspective view illustrating a state where the upper heat insulation member 121 is further attached to the upper surface side of the frame body 110 from the state of FIG. 9.

[0065] As illustrated in FIGS. 4 and 10, the upper heat insulation member 121 is formed in a strip plate shape elongated in the roof longitudinal direction. In the present embodiment, eight upper heat insulation members 121 are provided in total. Each of the upper heat insulation members 121 is made of, for example, a hard heat insulation material such as extruded expanded polystyrene. However, each upper heat insulation member 121 may be made of a fiber-based heat insulation material such as cellulose fiber, rock wool, or glass wool.

[0066] The eight upper heat insulation members 121 are disposed so as to fill the spaces 113 extending in the roof longitudinal direction facing the side surfaces of the rafter members 111. Each space 113 is a space opened upward with the flat sheet portion 141a of the roof side moisture-proof sheet 141 as a bottom surface. In each space 113, two upper heat insulation members 121 are disposed side by side without a gap in the roof longitudinal direction. These eight upper heat insulation members 121 are fixed to the frame body 110 by screws 104. The lateral width dimension of each of the upper heat insulation members 121 is set so as to be accommodated in a space formed between the side surfaces of each of the rafter members 111. Furthermore, the dimension of the upper heat insulation member 121 in the roof longitudinal direction is set to such a length that at least the entire space between the ridge beam 22 and the eaves beam 24 is closed when the two upper heat insulation members 121 are arranged without a gap in the roof longitudinal direction. In the example of FIG. 10, the upper heat insulation member 121 on the ridge side is formed longer than the upper heat insulation member 121 on the eaves side in the roof longitudinal direction, but the magnitude relationship of the length is not limited thereto. Furthermore, a thickness T1 (see FIG. 4) of the upper heat insulation member 121 is larger than a thickness T2 of the lower heat insulation member 131. Here, the thickness is a thickness in a direction perpendicular to the roof surface. In FIG. 4, as an example, the thickness T1 of the upper heat insulation member 121 is set to 2 to 3 times the thickness T2 of the lower heat insulation member 131.

[0067] Referring to FIG. 4, the upper heat insulation member 121 located on the ridge side protrudes toward the ridge side from the lower heat insulation member 131 disposed below the upper heat insulation member. The ridge side end surface of the upper heat insulation member 121 is covered with a rectangular plate-shaped heat insulation member 171 (see FIG. 4) extending in the roof lateral direction. The heat insulation member 171 is made of, for example, ethylene-propylene rubber (EPT), and is fixed to the upper heat insulation member 121 with a nail 105 or the like (illustrated only in FIG. 10). As illustrated in FIG. 1, the heat insulation members 171 of the left and right roof panels 100 are disposed so as to abut each other on the upper side of the ridge beam 22 (boundary portion between the left and right roof panels 100).

[0068] Referring to FIG. 4, the upper heat insulation member 121 located on the eaves side has a protrusion 121a (corresponding to a protrusion of the upper heat insulation layer 120) protruding to the eaves side from the lower heat insulation member 131 located below the upper heat insulation member. On the lower surface of the protrusion 121a, the eaves beam attachment member 151 and a heat insulation member 170 are fixed side by side. The heat insulation member 170 is disposed on the eaves side with respect to the eaves beam attachment member 151. The heat insulation member 170 is an elongated member extending in the roof lateral direction, and is made of, for example, ethylene-propylene rubber (EPT).

[0069] As illustrated in FIG. 3, the heat insulation member 170 is formed in a trapezoidal cross-sectional shape so as to fill a space between an upper end surface of the outer heat insulation layer 32 provided on the side wall portion 30 of the building body 10 and a lower surface of a protruding portion of the upper heat insulation member 121. The protruding end surface of the upper heat insulation member 121, the outer surface of the heat insulation member 170, and the outer surface of the outer heat insulation layer 32 are flush with each other to form a vertical surface extending in the vertical direction.

[0070] Furthermore, in the installed state of the roof panel 100, the upper heat insulation layer 120 provided on the roof panel 100 of the left inclined roof portion 50L and the upper heat insulation layer 120 provided on the roof panel 100 of the right inclined roof portion 50R are connected via the heat insulation member 171 on the upper side of the ridge beam 22 (boundary portion between the left and right roof panels 100) (see FIG. 1). The upper heat insulation layers 120 of the connected left and right roof panels 100 form a heat insulation line (not illustrated) so as to surround the entire building outside the airtight line K in cooperation with the outer heat insulation layers 32 (see FIG. 1) provided on the left and right side wall portions 30 described above.

[0071] FIG. 11 is a perspective view illustrating a state in which the roof board 160 is attached to the upper side of the frame body 110 from the state of FIG. 10. In this example, four roof boards 160 are provided. These four roof boards 160 are arranged in two rows and two columns so as to cover the entire upper side of the frame body 110. Each of the roof boards 160 is formed of a rectangular plate material elongated in the roof longitudinal direction, and is disposed in contact with an upper end surface of each of the rafter members 111 of the frame body 110. Each of the roof boards 160 is fixed to the frame body 110 by a nail 106.

[0072] As illustrated in FIG. 3, there is a gap between the lower surface of each of the roof boards 160 and the upper surface of the upper heat insulation member 121. This gap constitutes a roof side ventilation passage 161 extending in the roof longitudinal direction along the rafter member 111. The roof side ventilation passages 161 are formed on the roof panels 100 of the left and right inclined roof portions 50L and 50R, and the left and right roof side ventilation passages 161 communicate with each other on the upper side of the ridge beam 22 (see FIG. 1). A lower end portion of each of the roof side ventilation passages 161 communicates with an upper end portion of the wall side ventilation passage 37 through a space between the plurality of rafter members 111. Accordingly, as indicated by broken line arrows in FIG. 3, it is possible to ventilate high-humidity air containing moisture through the wall side ventilation passage 37 and the roof side ventilation passage 161.Procedure for Assembling Roof Panel

[0073] The configuration of the roof panel 100 and the building 1 including the roof panel 100 has been described above. FIGS. 6 to 10 described above are extracted perspective views of respective members of the roof panel 100, and are also understood as assembly procedure diagrams. Hereinafter, this assembly procedure will be briefly described. When the roof panel 100 is assembled, first, the frame body 110 is prepared (see FIG. 6), and the roof side moisture-proof sheet 141 and the eaves beam attachment member 151 are directly attached to the lower end surface of the prepared frame body 110 (see FIG. 7). At this time, first, the eaves beam attachment member 151 is attached to the frame body 110, and one end portion of the roof side moisture-proof sheet 141 is bent along the vertical end surface 151b (see FIG. 4) of the eaves beam attachment member 151 to form the lower extending sheet portion 141b. After the attachment of the eaves beam attachment member 151 and the roof side moisture-proof sheet 141 is completed, the purlin attachment member 150 is attached to the lower surface of the frame body 110 with the roof side moisture-proof sheet 141 interposed therebetween (see FIG. 8), and the lower heat insulation member 131 is fixed to the lower surface of the flat sheet portion 141a of the roof side moisture-proof sheet 141 (see FIG. 9). In this state, the upper heat insulation member 121 is fitted and fixed in each space 113 facing the side surface of each of the rafter members 111 of the frame body 110 (see FIG. 10). At this time, since the lower side of each space 113 is closed by the flat sheet portion 141a of the roof side moisture-proof sheet 141, the upper heat insulation member 121 does not fall downward. After the upper heat insulation member 121 is fixed, the roof board 160 is attached to the frame body 110 to complete the roof panel 100 (see FIG. 11). Note that the work of attaching the heat insulation member 170, 171 may be performed at an appropriate timing. Furthermore, the assembling procedure of the roof panel 100 described here is an example, and the present invention is not limited thereto.Procedure for Assembling Roof Panel to Building Body

[0074] When the completed roof panel 100 (see FIG. 4) is assembled to the building body 10, the roof panel 100 is fixed to the upper surface of the eaves beam 24, the upper surface of the purlin 23, and the upper surface of the ridge beam moisture-proof sheet 29 with screws or the like. Specifically, after the roof panel 100 is tilted and aligned at an angle corresponding to the roof gradient on the upper side of the ridge beam 22, the purlin 23, and the eaves beam 24, the roof panel 100 is moved downward as indicated by a white arrow in FIG. 4 to be fixed. Then, the work of assembling the roof panel 100 is completed.

[0075] Then, when the assembling of the roof panel 100 is completed, as illustrated in FIG. 3, the lower end surface of the lower extending sheet portion 141b of the roof side moisture-proof sheet 141 (roof side airtight layer 140) and the upper end surface of the body side moisture-proof sheet 35 (body side airtight layer 39) abut on each other. As a result, since the body side airtight layer 39 and the roof side airtight layer 140 are continuously connected, a continuous airtight line K extending from the side wall portion 30 side of the building body 10 to the roof 50 side is formed as illustrated in FIG. 1. The airtight lines K are formed on both left and right sides of the ridge beam 22. The left and right airtight lines K are continuously connected via the ridge beam moisture-proof sheet 29 covering the upper surface of the ridge beam 22.

[0076] Note that the airtight line K is a moisture-proof line that is also used for airtightness and is a line in which a surface on which air circulation between the indoor space IS side and the outdoor space OS side is blocked is viewed from the roof lateral direction. If the airtight line K is interrupted in the middle, the airtightness and the moisture resistance of the building 1 are impaired at the interrupted portion. However, in this example, since the airtight line K is continuously connected, the airtightness of the building 1 can be maintained high.Operation and Effect

[0077] As described above, the roof panel 100 according to the present embodiment includes the frame body 110, the upper heat insulation layer 120 and the lower heat insulation layer 130 that are supported by the frame body 110 and disposed side by side, one above the other, and the roof side airtight layer 140 interposed between the upper heat insulation layer 120 and the lower heat insulation layer 130. Then, the thickness T1 of the upper heat insulation layer 120 is set larger than the thickness T2 of the lower heat insulation layer 130.

[0078] According to the roof panel 100, the upper heat insulation layer 120, the lower heat insulation layer 130, and the roof side airtight layer 140 are supported by one frame body 110 to be unitized. Therefore, a worker can complete the installation work of each layer 120, 130, 140 only by installing the roof panel 100, and the work efficiency can be remarkably improved. That is, in a case where such a unitized roof panel 100 is not used, the worker needs to dispose the roof side airtight layer at a position sandwiched between the heat insulation layers, and the work is very difficult. On the other hand, according to the roof panel 100, since the upper heat insulation layer 120, the lower heat insulation layer 130, and the roof side airtight layer 140 are supported by one frame body 110, and the positional relationship therebetween is fixed in advance, the work becomes easier than the case where these layers 120, 130 and 140 are individually installed.

[0079] Furthermore, since the roof side airtight layer 140 (see FIG. 3) is disposed between the upper heat insulation layer 120 and the lower heat insulation layer 130, it is possible to effectively suppress the summer type dew condensation and the winter type dew condensation in each heat insulation layer 120, 130. That is, in winter, upper heat insulation layer 120 can suppress cooling of roof side airtight layer 140 due to low-temperature outside air. Therefore, even if the high-humidity air in the indoor space IS passes through the lower heat insulation layer 130 and reaches the roof side airtight layer 140, the cooling of the air by the roof side airtight layer 140 is suppressed, so that the generation of dew condensation is also suppressed. Furthermore, in the summer season, the lower heat insulation layer 130 can suppress cooling of the roof side airtight layer 140 by the air in the indoor space IS cooled by the air conditioner. Therefore, even if the high-humidity air from the outdoor space OS passes through the upper heat insulation layer 120 and reaches the roof side airtight layer 140, the cooling of the air by the roof side airtight layer 140 is suppressed, so that the generation of dew condensation is also suppressed.

[0080] Here, the temperature of the low-temperature side space in winter (in this case, the outdoor space OS) decreases to near 0° C., whereas the temperature of the low-temperature side space in summer (In this case, indoor space IS) is at most about 20° C. Therefore, in the winter season, the roof side airtight layer 140 is significantly cooled by the low-temperature air in the outdoor space OS as compared with the summer season. Therefore, in the roof panel 100, by setting the thickness T1 of the upper heat insulation layer 120 (that is, the thickness of the heat insulation layer on the outdoor space OS side) to be larger than the thickness T2 of the lower heat insulation layer 130 (the thickness of the heat insulation layer on the indoor space side), the temperature decrease of the roof side airtight layer 140 in the winter season is sufficiently suppressed. This makes it possible to effectively suppress the occurrence of winter type dew condensation. Therefore, according to the roof panel 100, it is possible to effectively suppress both the winter type dew condensation and the summer type dew condensation while filling measures against the winter type dew condensation.

[0081] Furthermore, in the roof panel 100 according to the present embodiment, the roof side airtight layer 140 is configured to be connected to the body side airtight layer 39 provided in the building body 10 in the installed state (see FIG. 3). When the roof side airtight layer 140 and the body side airtight layer 39 are connected, the above-described airtight line K (see FIG. 1) is formed, so that the worker does not need to perform the work of forming the airtight line K separately from the work of installing the roof panel 100, and the work can be efficiently performed.

[0082] In the roof panel 100 according to the present embodiment, the roof side airtight layer 140 includes, in the installed state, the flat sheet portion 141a (intervening portion) interposed between the upper heat insulation layer 120 and the lower heat insulation layer 130, and the lower extending sheet portion 141b (non-intervening portion) connected to the eaves side end edge of the flat sheet portion 141a, and the lower extending sheet portion 141b is connected to the body side airtight layer 39 in the installed state (see FIG. 3). According to this, the roof side airtight layer 140 and the body side airtight layer 39 provided at a position spaced apart from the roof side airtight layer 140 can be easily connected using the lower extending sheet portion 141b.

[0083] Moreover, in the roof panel 100 according to the present embodiment, the lower extending sheet portion 141b is formed to extend downward from the extension line of the flat sheet portion 141a when viewed from the roof lateral direction (see FIG. 3). According to this, the roof side airtight layer 140 and the body side airtight layer 39 disposed at a position spaced apart from each other on the lower side thereof can be more easily connected using the lower extending sheet portion 141b.

[0084] Furthermore, the roof panel 100 according to the present embodiment includes the eaves beam attachment member 151 that is interposed between the frame body 110 and the eaves beam 24 in the installed state to hold the inclination angle of the plurality of rafter members 111 with respect to the left and right direction (an example of the horizontal direction) at a predetermined angle. The lower surface 151c of the eaves beam attachment member 151 is configured to be horizontally supported by the eaves beam 24 in the installed state of the roof panel 100 (see FIG. 3). Accordingly, when the roof panel 100 is installed, the frame body 110 can be prevented from falling along the roof gradient. Accordingly, installation workability of the roof panel 100 can be improved.

[0085] Moreover, in the roof panel 100 according to the present embodiment, in the installed state, the eaves beam attachment member 151 is disposed so as to face the lower heat insulation layer 130 in the roof longitudinal direction, and the lower extending sheet portion 141b of the roof side moisture-proof sheet 141 is disposed so as to be sandwiched between the eaves beam attachment member 151 and the lower heat insulation layer 130 (see FIG. 3). With such a configuration, the lower extending sheet portion 141b of the roof side moisture-proof sheet 141 is firmly fixed between the eaves beam attachment member 151 and the lower heat insulation layer 130. Therefore, it is possible to reliably connect the roof side airtight layer 140 and the body side airtight layer 39 using the lower extending sheet portion 141b while maintaining the position of the lower extending sheet portion 141b constant.

[0086] Furthermore, in the roof panel 100 according to the present embodiment, the lower end surface (an example of the lower end portion) of the lower extending sheet portion 141b of the roof side moisture-proof sheet 141 is configured to be exposed downward from between the eaves beam attachment member 151 and the lower heat insulation layer 130 and connected to the body side airtight layer 39 (see FIG. 3). According to this, since the lower end surface of the lower extending sheet portion 141b is exposed, the lower end surface of the lower extending sheet portion 141b can be easily connected to the body side airtight layer 39. This facilitates formation of the airtight line K (see FIG. 1) by connection between the roof side airtight layer 140 and the body side airtight layer 39.

[0087] In addition, in the roof panel 100 according to the present embodiment, the lower end surface of the lower extending sheet portion 141b of the roof side moisture-proof sheet 141 is located at the same height as the lower surface 151c of the eaves beam attachment member 151 in the installed state (see FIG. 3). According to this, since the lower end surface of the lower extending sheet portion 141b of the roof side moisture-proof sheet 141 and the lower surface of the eaves beam attachment member 151 are flush with each other, when the eaves beam attachment member 151 is attached to the upper surface of the eaves beam 24, the lower extending sheet portion 141b does not interfere and the work can be easily performed. Furthermore, only by installing the roof panel 100, the lower end surface of the lower extending sheet portion 141b and the upper end surface of the body side airtight layer 39 abut on each other, and the roof side airtight layer 140 and the body side airtight layer 39 are connected. Therefore, the work efficiency can be improved. Furthermore, since it is not necessary to overlap the lower extending sheet portion 141b of the roof side moisture-proof sheet 141 in the thickness direction of the body side airtight layer 39, it is possible to save the length of the lower extending sheet portion 141b and reduce the material cost.

[0088] Furthermore, in the roof panel 100 according to the present embodiment, the upper heat insulation member 121 constituting the upper heat insulation layer 120 is disposed in the space 113 formed by the plurality of rafter members 111 and the roof side moisture-proof sheet 141 in the frame body 110 (see FIG. 10). With such a configuration, when a worker places the upper heat insulation member 121 in the space 113, by attaching the roof side moisture-proof sheet 141 to the frame body 110 in advance, it is possible to prevent the upper heat insulation member 121 from falling off from the space 113. Therefore, workability of attaching the upper heat insulation member 121 to the frame body 110 can be improved.

[0089] Furthermore, the roof panel 100 according to the present embodiment further includes a roof board 160 that abuts on upper end surfaces of the plurality of rafter members 111 in the frame body 110 and covers the upper side of the frame body 110. The upper heat insulation layer 120 is configured to form the roof side ventilation passage 161 extending in the roof longitudinal direction between an upper surface of the upper heat insulation layer and the roof board 160 (see FIG. 3). According to this, the high-humidity air in the roof panel 100 can be ventilated through the roof side ventilation passage 161. Therefore, it is possible to prevent high-humidity air from staying in the roof panel 100 to cause dew condensation.

[0090] Furthermore, in the roof panel 100 according to the present embodiment, the frame body 110 further includes a coupling member 112 that extends in the roof lateral direction and connects eaves side end portions of the plurality of rafter members 111. The coupling member 112 is disposed at a position spaced apart from the protrusion 121a of the upper heat insulation layer 120 toward the eaves side. The communication passage 162 partitioned by the plurality of rafter members 111 and communicating with the roof side ventilation passage 161 is formed between the coupling member 112 and the protrusion 121a of the upper heat insulation layer 120 (see FIG. 3). According to this, it is possible to secure the communication passage 162 to the roof side ventilation passage 161 with a simple configuration without forming a communication hole in each heat insulation layer 120, 130 or the frame body 110. In the example of the present embodiment, the air ventilation passage can be easily configured by communicating the wall side ventilation passage 37 and the roof side ventilation passage 161 using the communication passage 162.

[0091] Furthermore, in the building 1 including the roof panel 100 according to the present embodiment, the body side moisture-proof sheet 35 constituting the body side airtight layer 39 is attached to the interior side surface of the eaves beam 24 and the interior side surface of the pillar member 38 and extends in the vertical direction. The roof side airtight layer 140 constituted by the roof side moisture-proof sheet 141 of the roof panel 100 cooperates with the body side airtight layer 39 to form an airtight line K (see FIG. 1) continuous from the side wall portion 30 side to the roof 50 side when viewed from the roof lateral direction. According to this, the airtight line K is continuously connected from the side wall portion 30 side to the roof 50 side, so that airtightness can be secured even at the connection portion between the side wall portion 30 of the building body 10 and the roof 50. Therefore, the generation of the winter type dew condensation and the summer type dew condensation can be more reliably suppressed.

[0092] Furthermore, in the building 1 including the roof panel 100 according to the present embodiment, the upper heat insulation layer 120 provided on the roof panel 100 has the protrusion 121a protruding to the eaves side (the roof outer side) from the lower heat insulation layer 130 in the roof longitudinal direction, and the protrusion 121a is configured to be located above the outer heat insulation layer 32 provided on the side wall portion 30 in the installed state of the roof panel 100. With such a configuration, the respective heat insulation layers 32 and 120 can be disposed so as to surround the outer side of the airtight line I by the upper heat insulation layer 120 of the roof panel 100 and the outer heat insulation layer 32 of the side wall portion 30 of the building body 10 (see FIG. 1). Therefore, the roof side airtight layer 140 and the body side airtight layer 39 constituting the airtight line I can be suppressed from being cooled by the cold air of the outdoor space OS, and the generation of the winter type dew condensation can be suppressed. Furthermore, the heat insulation property of the entire building 1 can be improved to keep the temperature of the interior space S1 comfortable.

[0093] Furthermore, in the building 1 including the roof panel 100 according to the present embodiment, the wall side ventilation passage 37 extending in the vertical direction is formed between the outer heat insulation layer 32 and the outer wall panel 31 in the side wall portion 30, and the wall side ventilation passage 37 communicates with the roof side ventilation passage 161 in the roof panel 100 through the space between the plurality of rafter members 111 (see FIG. 3). According to this, for example, the high-humidity air leaking from the indoor space IS or the high-humidity air entering the indoor side of the outer wall panel 31 from the outdoor space OS is ventilated through the wall side ventilation passage 37 and the roof side ventilation passage 161 as indicated by the dashed arrow in FIG. 3. Therefore, it is possible to suppress the occurrence of dew condensation in the side wall portion 30.

[0094] In the building 1 including the roof panel 100 according to the present embodiment, the roof side airtight layers 140 of the left and right inclined roof portions 50L and 50R are coupled to each other via the ridge beam moisture-proof sheet 29 on the upper side (boundary portion between both inclined roof portions 50L and 50R) of the ridge beam 22 when viewed from the roof lateral direction (see FIG. 1). According to this, the roof side airtight layers 140 of the pair of inclined roof portions 50L and 50R are continuously connected without interruption on the upper side of the ridge beam 22. Therefore, since the left and right airtight lines K are continuously connected on the upper side of the ridge beam 22, it is possible to prevent the airtightness of the building 1 from being impaired at the boundary portions of both the inclined roof portions 50L and 50R.

[0095] Furthermore, in the building 1 including the roof panel 100 according to the present embodiment, the upper heat insulation layers 120 of the left and right inclined roof portions 50L and 50R are coupled to each other on the upper side (boundary portion between both inclined roof portions 50L and 50R) of the ridge beam 22 when viewed from the roof lateral direction (see FIG. 1). According to this, the upper heat insulation layers 120 of the pair of inclined roof portions 50L and 50R are continuously connected without interruption on the upper side of the ridge beam 22 to form one heat insulation line (not illustrated). Therefore, it is possible to prevent the heat insulation line from being interrupted on the upper side (that is, a boundary portion between the pair of inclined roof portions 50L and 50R) of the ridge beam 22 and the heat insulation property of the building 1 from being impaired.Other Modified Embodiments

[0096] Although the roof panel 100 and the building 1 according to the embodiment of the present invention have been described above, the present invention is not limited thereto, and for example, the following modified embodiments can be adopted. Note that, in the following description of modified embodiments, members having the same configurations as those of the previous embodiments are denoted by the same reference signs.

[0097] (1) FIG. 12A illustrates a first modified embodiment. FIG. 12A is a view corresponding to a partial cross-sectional view of the left end in FIG. 4. In the first modified embodiment, the configuration of the lower extending sheet portion 141b of the roof side moisture-proof sheet 141 is different from that of the previous embodiment. That is, in the present modified embodiment, the lower extending sheet portion 141b protrudes downward from the lower end position of the eaves beam attachment member 151. According to this configuration, in the installed state of the roof panel 100, the lower end portion of the lower extending sheet portion 141b (a part of the roof side airtight layer 140) can be connected (fixed) to the upper end portion of the body side airtight layer 39 in an overlapping manner from the inside. Thus, a sufficient connection margin between the roof side airtight layer 140 and the body side airtight layer 39 can be secured. Therefore, it is possible to prevent the continuity of the airtight line K (see FIG. 1) from being impaired at the connection portion between the roof side airtight layer 140 and the body side airtight layer 39. In addition, it is possible to reliably obtain the same operation and effect as those of the previous embodiment in which the continuity of the airtight line K is secured to effectively suppress both the summer type dew condensation and the winter type dew condensation.

[0098] (2) FIG. 12B illustrates a second modified embodiment. The second modified embodiment is different from the first modified embodiment in that the eaves beam attachment member 151 is configured separately from the roof panel 100 and is fixed to the upper surface of the eaves beam 24 in advance. Also with this configuration, similarly to the first modified embodiment, it is possible to obtain an effect that the airtight line K is formed by connecting the roof side airtight layer 140 and the body side airtight layer 39.

[0099] (3) FIG. 13A illustrates a third modified embodiment. In the third modified embodiment, the configuration of the roof side airtight layer 140 is different from that of the previous embodiment. That is, in the present third modified embodiment, the roof side airtight layer 140 includes a roof side moisture-proof sheet 141 and an eaves beam attachment member 152.

[0100] The roof side moisture-proof sheet 141 does not have the lower extending sheet portion 141b in FIG. 3, and is formed only of the flat sheet portion 141a. The eaves side end surface of the flat sheet portion 141a is connected in contact with a vertical end surface 152b of the eaves beam attachment member 152. In this case, the roof side moisture-proof sheet 141 corresponds to an intervening portion interposed between the upper heat insulation layer 120 and the lower heat insulation layer 130, and the eaves beam attachment member 152 corresponds to a non-intervening portion connected to the intervening portion.

[0101] The eaves beam attachment member 152 has the same shape as the eaves beam attachment member 151 of the previous embodiment, but is made of a different material. That is, the eaves beam attachment member 152 is made of a member exhibiting airtightness, for example, resin or metal. Furthermore, the eaves beam attachment member 152 may be formed by coating a surface of wood with resin or metal.

[0102] An inclined surface 152a, the vertical end surface 152b, and a lower surface 152c of the eaves beam attachment member 152 respectively correspond to the inclined surface 151a, the vertical end surface 151b, and the lower surface 151c of the eaves beam attachment member 151 in the previous embodiment, but are different from those in the previous embodiment in the following points. That is, the eaves beam attachment member 152 is formed such that the lower surface 152c of the eaves beam attachment member abuts not only the upper surface of the eaves beam 24 but also the upper end surface of the body side airtight layer 39 in the installed state of the roof panel 100. By this abutment, the roof side airtight layer 140 including the eaves beam attachment member 152 and the roof side moisture-proof sheet 141 is connected to the body side airtight layer 39. Therefore, it is possible to form the airtight line K by connecting the roof side airtight layer 140 and the body side airtight layer 39 only by installing the roof panel 100. Furthermore, since the eaves beam attachment member 152 constituting the roof side airtight layer 140 has higher rigidity and less positional variation than the sheet-like member, it is possible to reliably connect the roof side airtight layer 140 and the body side airtight layer 39 via the eaves beam attachment member 152. Therefore, similarly to the above embodiment, it is possible to obtain an effect that the airtight line K is formed by connecting the roof side airtight layer 140 and the body side airtight layer 39.

[0103] (4) FIG. 13B illustrates a fourth modified embodiment. The fourth modified embodiment is different from the third modified embodiment in that the eaves beam attachment member 152 is configured separately from the roof panel 100 and is fixed to the upper end surfaces of the eaves beam 24 and the body side moisture-proof sheet 35 in advance. In the present modified embodiment, the body side airtight layer 39 is formed of the eaves beam attachment member 152 and the body side moisture-proof sheet 35. Also with this configuration, it is possible to obtain an effect that the airtight line K is formed by connecting the roof side airtight layer 140 and the body side airtight layer 39 similarly to the above-described third modified embodiment.

[0104] (5) In the above embodiment, the horizontal members 21 (ridge beam 22, purlin 23 and eaves beam 24) provided in the building body 10 are made of wood, but the present invention is not limited thereto, and may be made of a metal member such as a steel frame. In this case, the eaves beam 24 itself forms a part of the body side airtight layer 39 to form the airtight line K. However, moreover, foamed urethane may be sprayed to the inner side surface of the metal eaves beam 24 to form the foamed urethane as a part of the body side airtight layer 39. Note that urethane foam may be sprayed onto the inner side surface of the wooden eaves beam 24 to form the urethane foam as a part of the body side airtight layer 39. Furthermore, as described in the above embodiment, depending on the required airtightness level, even if the eaves beam 24 is made of wood, a part of the airtight line K can be constituted by the eaves beam 24.

[0105] (6) The eaves beam attachment member 151 according to the above embodiment and the eaves beam attachment member 152 according to the third and fourth modified embodiments are formed to have a triangular cross section, but the present invention is not limited thereto. For example, the eaves beam attachment member may be formed to have a trapezoidal cross section obtained by cutting a top portion of a triangle into a flat surface shape. That is, the eaves beam attachment member 151, 152 may have any shape as long as it can hold the inclination angle of the frame body 110 with respect to the horizontal direction at a predetermined angle. Furthermore, the lower surface of the eaves beam attachment member 151, 152 is not necessarily formed in a planar shape, and may be formed to be in line contact with the upper surface of the eaves beam 24 along a line extending in the roof lateral direction.

[0106] (7) In the above embodiment, the eaves beam attachment member 151 is made of wood, but is not limited thereto, and may be made of, for example, a metal fitting formed by bending a sheet metal.

[0107] (8) The eaves beam attachment member 151 in the above embodiment and the eaves beam attachment member 152 in the third and fourth modified embodiments are not limited to one member extending in the roof lateral direction along the horizontal member 21, and may be, for example, a plurality of members arranged at intervals in the roof lateral direction. However, in this case, in order to form the stable airtight line K, it is preferable to directly connect the eaves beam attachment member 151, 152 and the roof side moisture-proof sheet 141, which is the roof side airtight layer 140, to the body side airtight layer 39 as in the above embodiment.

[0108] (9) In the above embodiment, the pedestal member 27 (see FIG. 4) covered with the ridge beam moisture-proof sheet 29 is fixed to the upper surface of the ridge beam 22 in advance, but the present invention is not limited thereto. For example, the pedestal member 27 covered with the ridge beam moisture-proof sheet 29 may be attached to one of the left and right roof panels 100 in FIG. 4 in advance.

[0109] (10) In the above embodiment, the roof side airtight layer 140 is formed of the roof side moisture-proof sheet 141, but is not limited thereto, and may be formed of, for example, a waterproof paint formed by spraying or painting on the surface of the heat insulation member. Furthermore, the method for constructing the roof side airtight layer 140 is not limited to the construction procedure in which the roof side moisture-proof sheet 141 is first attached to the frame body 110 and then the lower heat insulation member 131 is attached as illustrated in FIGS. 7 and 8. For example, the roof side moisture-proof sheet 141 or a waterproof paint or the like as the roof side airtight layer 140 may be provided in advance on the lower heat insulation member 131, and then the lower heat insulation member 131 may be attached to the frame body 110 together with the roof side airtight layer 140. That is, a method for providing the roof side airtight layer 140 between the upper heat insulation layer 120 and the lower heat insulation layer 130 may be any method (and procedure).

[0110] (11) In the above embodiment, after the roof side moisture-proof sheet 141 is fixed to the lower surface of the rafter member 111 in the frame body 110, the lower heat insulation member 131 is fixed to the lower surface of the roof side moisture-proof sheet 141. However, the present invention is not limited to this. For example, after an intermediate heat insulation member (not illustrated) is disposed on the lower surface of the rafter member 111, the roof side moisture-proof sheet 141 may be disposed on the lower surface of the intermediate heat insulation member, and the lower heat insulation member 131 may be fixed to the lower surface of the roof side moisture-proof sheet 141. After the lower heat insulation member 131 is disposed, the upper heat insulation member 121 may be disposed in a space facing the side surface of each of the rafter members 111 (the bottom surface of the space is constituted by the intermediate heat insulation member) as in the above embodiment. In the roof panel 100 (not illustrated) created in this manner, the upper heat insulation layer 120 includes two layers of the upper heat insulation member 121 and the intermediate heat insulation member located above the roof side moisture-proof sheet 141, while the lower heat insulation layer 130 includes only the lower heat insulation member 131 located below the roof side moisture-proof sheet 141 as in the above embodiment. Accordingly, the thickness of the upper heat insulation layer 120 can be set sufficiently larger than the thickness of the lower heat insulation layer 130. Note that the procedure of creating the roof panel 100 in this case is not limited to the above-described procedure.

[0111] (12) In the above embodiment, the roof 50 to which the roof panel 100 is applied is configured by a gable roof, but is not limited thereto, and may be configured by, for example, a side roof, a hip roof, or the like. Furthermore, the roof 50 is not limited to these inclined roofs, and may be formed of, for example, a land roof having no inclination.

[0112] (13) The present invention includes any combination of the foregoing embodiments and the respective modified embodiments.

[0113] Note that the above-described specific embodiments of the present invention mainly include inventions having the following configurations. That is, a roof panel according to a first invention is a roof panel installed across and on an upper side of a plurality of horizontal members, the plurality of horizontal members extending in a roof lateral direction and arranged at intervals in a roof longitudinal direction orthogonal to the roof lateral direction, the roof panel including: a frame body disposed across the plurality of horizontal members in an installed state of the roof panel; an upper heat insulation layer and a lower heat insulation layer that are supported by the frame body and are disposed side by side, one above another; and a roof side airtight layer interposed between the upper heat insulation layer and the lower heat insulation layer, in which a thickness of the upper heat insulation layer is larger than a thickness of the lower heat insulation layer.

[0114] According to this roof panel, the upper heat insulation layer, the lower heat insulation layer, and the roof side airtight layer are supported by one frame body to be unitized. Therefore, a worker can complete the installation work of each layer only by installing the roof panel, and the work efficiency can be remarkably improved. That is, in a case where such a unitized roof panel is not used, the worker needs to form an airtight line by disposing the roof side airtight layer at a location sandwiched by the heat insulation layers, and the work becomes very difficult. On the other hand, according to the roof panel, since the upper heat insulation layer, the lower heat insulation layer, and the roof side airtight layer are supported by the frame body in advance and a positional relationship between the upper heat insulation layer, the lower heat insulation layer, and the roof side airtight layer is fixed, the work becomes easy as compared with the case where these layers are individually installed. In the present specification, the “airtight layer” is defined as a moisture-proof layer that also serves as airtight. Furthermore, the airtight line is defined as a moisture-proof line that is also used for airtightness, the moisture-proof line being a line in which a surface on which air circulation between an indoor space side and an outdoor space side is blocked is viewed from the roof lateral direction.

[0115] Then, since the roof side airtight layer is disposed between the upper heat insulation layer and the lower heat insulation layer, it is possible to effectively suppress summer type dew condensation and winter type dew condensation in each heat insulation layer. That is, in winter, the upper heat insulation layer can suppress cooling of the roof side airtight layer by low-temperature outside air. Therefore, even if the high-humidity air in the building passes through the lower heat insulation layer and reaches the roof side airtight layer, the cooling of the air by the roof side airtight layer is suppressed, so that the generation of dew condensation (winter type dew condensation) is also suppressed. Furthermore, in summer, the lower heat insulation layer can suppress cooling of the roof side airtight layer by the air in the building cooled by an air conditioner. Therefore, even if the high-humidity air outside the building passes through the upper heat insulation layer and reaches the roof side airtight layer, the cooling of the air by the roof side airtight layer is suppressed, so that the generation of dew condensation (summer type dew condensation) is also suppressed.

[0116] Here, the temperature of the low-temperature side space (in this case, the outdoor space) in winter decreases to near 0° C., whereas the temperature of the low-temperature side space (in this case, the indoor space) in summer is at most about 20° C. Therefore, in the winter season, the roof side airtight layer is significantly cooled by the low-temperature air in the outdoor space as compared with the summer season. Therefore, in the roof panel, by setting the thickness of the upper heat insulation layer (that is, the thickness of the heat insulation layer on the outdoor space side) to be larger than the thickness of the lower heat insulation layer (the thickness of the heat insulation layer on the indoor space side), it is possible to sufficiently suppress the cooling (temperature decrease) of the roof side airtight layer in winter. As a result, the generation of the winter type dew condensation can be effectively suppressed. Therefore, according to the roof panel, it is possible to effectively suppress both the winter type dew condensation and the summer type dew condensation while filling measures against the winter type dew condensation.

[0117] A roof panel according to a second invention is the roof panel according to the first invention, in which the roof side airtight layer is preferably connected to a body side airtight layer provided in a building body including the plurality of horizontal members in the installed state.

[0118] According to this configuration, when the worker completes the installation work of the roof panel, the roof side airtight layer provided on the roof panel is connected to the body side airtight layer provided on the building body, and one continuous airtight line from the building body side to the roof side is formed. Therefore, work efficiency associated with installation of the roof panel can be remarkably improved. That is, in the conventional roof panel, the worker needs to perform a lot of work for forming the airtight line separately from the installation work of the roof panel, but according to this configuration, the work man-hours required for forming the airtight line is greatly reduced, so that the work efficiency is improved.

[0119] A roof panel according to a third invention is the roof panel according to the second invention, in which the roof side airtight layer preferably includes, in the installed state, a sheet-like intervening portion that is interposed between the upper heat insulation layer and the lower heat insulation layer and extends in the roof longitudinal direction, and a non-intervening portion that is connected to an edge of the intervening portion on a roof outer side in the roof longitudinal direction, and the non-intervening portion is preferably connected to the body side airtight layer in the installed state.

[0120] According to this configuration, the roof side airtight layer can be easily connected to the body side airtight layer using the non-intervening portion of the roof side airtight layer. Therefore, even when the body side airtight layer is located at a position slightly away from a boundary region between the upper heat insulation layer and the lower heat insulation layer, the roof side airtight layer and the body side airtight layer can be connected using the non-intervening portion provided in the roof side airtight layer. Therefore, both the airtight layers can be reliably connected while increasing the degree of freedom in a relative positional relationship (arrangement position) between the body side airtight layer and each heat insulation layer.

[0121] A roof panel according to a fourth invention is the roof panel according to the third invention, in which the non-intervening portion is preferably formed so as to extend downward from an extension line of the intervening portion as viewed in the roof lateral direction.

[0122] According to this configuration, it is possible to more reliably connect the roof side airtight layer and the body side airtight layer using the non-intervening portion of the roof side airtight layer. That is, the body side airtight layer provided in the building body is usually disposed below the roof side airtight layer. The inventors paid attention to this point, and extended the non-intervening portion of the roof side airtight layer downward from the extension line of the sheet-like intervening portion. As a result, the roof side airtight layer and the body side airtight layer located downward from the roof side airtight layer can be reliably connected by the non-intervening portion.

[0123] A roof panel according to a fifth invention is the roof panel according to the third or fourth invention, in which a roof formed by the roof panel is preferably an inclined roof, the roof panel preferably further includes an attachment member that is interposed between the frame body and an outermost horizontal member that is the horizontal member located on a most roof outer side in the roof longitudinal direction in the installed state to hold an inclination angle of a plurality of rafter members with respect to a horizontal direction at a predetermined angle, and the attachment member is preferably fixed to a portion corresponding to the outermost horizontal member in the frame body, and a lower end portion of the attachment member is preferably horizontally supported by the outermost horizontal member in the installed state.

[0124] According to this configuration, when the roof panel is installed on an upper side of the plurality of horizontal members, the lower end portion of the attachment member fixed to the frame body is horizontally supported from the lower side by the outermost horizontal member. Therefore, when the roof panel is installed, the frame body can be prevented from falling along a roof gradient. Accordingly, installation workability of the roof panel can be improved.

[0125] A roof panel according to a sixth invention is the roof panel according to the fifth invention, in which the non-intervening portion of the roof side airtight layer preferably includes the attachment member.

[0126] According to this configuration, it is possible to reliably connect the roof side airtight layer and the body side airtight layer using the non-intervening portion of the roof side airtight layer. That is, since the attachment member has a function of supporting the frame body on the upper surface of the outermost horizontal member, the attachment member is formed of a member having relatively high rigidity. By using such a member having high rigidity as the non-intervening portion of the roof side airtight layer, it is possible to suppress positional variation of the non-intervening portion as compared with, for example, a case where a resin sheet having flexibility is used as the non-intervening portion. Therefore, when the roof panel is installed, the position of the non-intervening portion does not vary and is maintained constant, so that the connection between the roof side airtight layer and the body side airtight layer using the non-intervening portion can be reliably performed. Furthermore, the cost can be reduced by using the existing attachment member as the non-intervening portion.

[0127] A roof panel according to a seventh invention is the roof panel according to the fifth invention, in which the attachment member is preferably disposed so as to face the lower heat insulation layer in the roof longitudinal direction, the non-intervening portion of the roof side airtight layer is preferably disposed to be sandwiched between the attachment member and the lower heat insulation layer, and a lower end portion of the non-intervening portion of the roof side airtight layer is preferably exposed downward from between the attachment member and the lower heat insulation layer in the installed state, and is preferably connected to the body side airtight layer.

[0128] According to this configuration, in the installed state of the roof panel, the lower end portion of the non-intervening portion of the roof side airtight layer is exposed downward from between the attachment member and the lower heat insulation layer, so that the lower end portion of the non-intervening portion can be easily connected to the body side airtight layer. Furthermore, the non-intervening portion of the roof side airtight layer can be sandwiched and firmly fixed between the attachment member and the lower heat insulation layer. Therefore, when the roof panel is installed, the position of the non-intervening portion of the roof side airtight layer is maintained constant without variation, so that the connection between the roof side airtight layer and the body side airtight layer using the non-intervening portion can be reliably performed.

[0129] A roof panel according to an eighth invention is the roof panel according to the seventh invention, in which a lower end surface of the non-intervening portion of the roof side airtight layer is preferably located at a height same as a lower surface of the attachment member in the installed state.

[0130] According to this configuration, since the lower end surface of the non-intervening portion of the roof side airtight layer and the lower surface of the attachment member are flush with each other, it is possible to improve the attachability when the attachment member is attached to the upper surface of the outermost horizontal member as compared with, for example, a case where the non-intervening portion protrudes downward from the lower surface of the attachment member. Furthermore, in this case, when the roof panel is installed, it is not necessary to overlap the non-intervening portion of the roof side airtight layer with the body side airtight layer, so that the length of the non-intervening portion can be saved and the material cost can be reduced.

[0131] A roof panel according to a ninth invention is the roof panel according to the seventh invention, in which the non-intervening portion of the roof side airtight layer preferably protrudes downward from a lower surface of the attachment member in the installed state.

[0132] According to this configuration, when the roof panel is installed, the portion protruding downward from the lower surface of the attachment member in the non-intervening portion of the roof side airtight layer is overlapped in a thickness direction of the body side airtight layer, so that the roof side airtight layer and the body side airtight layer can be connected to each other while a sufficient connection margin between the both is secured. Therefore, it is possible to prevent the continuity of the airtight line from being impaired at a connection portion between the roof side airtight layer and the body side airtight layer.

[0133] A roof panel according to a tenth invention is the roof panel according to any one of the first to ninth inventions, in which the frame body preferably includes a plurality of rafter members extending in the roof longitudinal direction across the plurality of horizontal members in the installed state and arranged at intervals in the roof lateral direction, the roof side airtight layer is preferably disposed so as to cover a lower surface side of the plurality of rafter members across the plurality of rafter members and is fixed to the frame body, and the upper heat insulation layer is preferably disposed in a space formed by the plurality of rafter members and the roof side airtight layer.

[0134] According to this configuration, the upper heat insulation layer is disposed in the space formed by the plurality of rafter members and the roof side airtight layer. A bottom surface of this space is constituted by the roof side airtight layer. Therefore, when the worker disposes the upper heat insulation layer in the space, the upper heat insulation layer can be prevented from falling off from the space by attaching the roof side airtight layer to the frame body in advance. Accordingly, workability of attaching the upper heat insulation layer to the frame body can be improved.

[0135] A roof panel according to an eleventh invention is the roof panel according to the tenth invention, preferably further including a roof board that abuts on upper end surfaces of the plurality of rafter members and covers an upper side of the frame body, in which the upper heat insulation layer preferably forms a roof side ventilation passage extending in the roof longitudinal direction between an upper surface of the upper heat insulation layer and the roof board.

[0136] According to this configuration, the high-humidity air in the roof panel can be ventilated through the roof side ventilation passage. Therefore, it is possible to prevent high-humidity air from staying in the roof panel to cause dew condensation.

[0137] A roof panel according to a twelfth invention is the roof panel according to the eleventh the invention, in which the upper heat insulation layer preferably includes a protrusion protruding beyond the lower heat insulation layer to a roof outer side in the roof longitudinal direction, the frame body preferably includes a coupling member that extends in the roof lateral direction, couples end portions of the plurality of rafter members on the roof outer side in the roof longitudinal direction, and is disposed at a position spaced apart from the protrusion of the upper heat insulation layer on the roof outer side in the roof longitudinal direction, and a communication passage partitioned by the plurality of rafter members and communicating with the roof side ventilation passage is preferably formed between the coupling member and the protrusion of the upper heat insulation layer.

[0138] According to this configuration, it is possible to secure the communication passage to the roof side ventilation passage with a simple configuration without forming a communication hole in each heat insulation layer or the frame body.

[0139] A building according to a thirteenth invention is a building including: a roof formed by the roof panel according to the first invention; and a building body including the plurality of horizontal members and having a ceiling side covered with the roof, in which the building body includes: an outermost horizontal member that is the horizontal member located on a most roof outer side in the roof longitudinal direction; a side wall portion including a plurality of pillar members connected to a lower surface of the outermost horizontal member as a framework; and a body side airtight layer that is attached to an interior side surface of the outermost horizontal member and an interior side surface of the pillar members and extends in a vertical direction to ensure airtightness between an outdoor space and an indoor space in the side wall portion, and the roof side airtight layer is connected to the body side airtight layer, and cooperates with the body side airtight layer to form an airtight line continuous from a side wall portion side to a roof side when viewed from the roof lateral direction.

[0140] According to this configuration, since the airtight line is continuously connected from the side wall portion side to the roof side, airtightness can be secured even at a connection portion between the side wall portion of the building body and the roof. Therefore, for example, in winter, it is possible to prevent high-humidity air in the indoor space from flowing into the upper heat insulation layer of the roof panel from the connection portion between the side wall portion of the building body and the roof and causing dew condensation. Furthermore, in the summer season, it is possible to prevent high-humidity air existing in the outdoor space from entering the lower heat insulation layer of the roof panel from the connection portion between the side wall portion of the building body and the roof and causing dew condensation.

[0141] A building according to a fourteenth invention is the building according to the thirteenth invention, in which the side wall portion preferably includes an outer heat insulation layer provided on an exterior side of the outermost horizontal member and extending in the vertical direction, the upper heat insulation layer of the roof panel preferably includes a protrusion protruding beyond the lower heat insulation layer to a roof outer side in the roof longitudinal direction, and the protrusion is preferably supported by the outermost horizontal member from below and is preferably located above an upper end portion of the outer heat insulation layer in an installed state of the roof panel.

[0142] According to this configuration, since the protrusion of the upper heat insulation layer is located above the outer heat insulation layer, the heat insulation layer can be disposed so as to surround the outside of the airtight line by the upper heat insulation layer of the roof panel and the outer heat insulation layer of the side wall portion of the building body when viewed from the roof lateral direction. Therefore, it is possible to suppress cooling of the roof side airtight layer and the body side airtight layer constituting the airtight line by cold air of the outdoor space, and to suppress generation of the above-described winter type dew condensation. Furthermore, it is possible to improve the heat insulation property of the entire building and to keep an interior temperature comfortable.

[0143] A building according to a fifteenth invention is the building according to the fourteenth invention, in which the roof panel preferably further includes a roof board that abuts on upper end surfaces of the plurality of rafter members and covers an upper side of the frame body, the upper heat insulation layer of the roof panel preferably forms a roof side ventilation passage extending in the roof longitudinal direction between the upper heat insulation layer of the roof panel and the roof board, the side wall portion preferably further includes an outer wall panel that is disposed on an exterior side of the outer heat insulation layer and forms a wall side ventilation passage extending in the vertical direction between the side wall portion and the outer heat insulation layer, and the wall side ventilation passage preferably communicates with the roof side ventilation passage through a space partitioned by the plurality of rafter members.

[0144] According to this configuration, for example, the high-humidity air leaking from the indoor space is ventilated through the wall side ventilation passage and the roof side ventilation passage. Therefore, the generation of dew condensation in the side wall portion can be suppressed.

[0145] A building according to a sixteenth invention is the building according to any one of the thirteenth to fifteenth inventions, in which the plurality of horizontal members preferably include a ridge beam and a pair of eaves beams disposed on both sides of the ridge beam with the ridge beam interposed between the eaves beams, the roof preferably includes a pair of inclined roof portions disposed on both sides of the ridge beam with the ridge beam interposed between the inclined roof portions and disposed across the ridge beam and each of the eaves beams, and the roof side airtight layers of the pair of inclined roof portions are preferably coupled to each other at a boundary portion between the both inclined roof portions on an upper side of the ridge beam when viewed from the roof lateral direction.

[0146] According to this configuration, the roof side airtight layers of the pair of inclined roof portions are continuously connected without interruption on the upper side of the ridge beam to form one airtight line. Therefore, it is possible to prevent the airtightness from being impaired due to interruption of the airtight line on the upper side of the ridge beam (that is, the boundary portion between the pair of inclined roof portions).

[0147] A building according to a seventeenth invention is the building according to any one of the thirteenth to fifteenth inventions, in which the plurality of horizontal members preferably include a ridge beam and a pair of eaves beams disposed on both sides of the ridge beam with the ridge beam interposed between the eaves beams, the roof preferably includes a pair of inclined roof portions disposed on both sides of the ridge beam with the ridge beam interposed between the inclined roof portions and disposed across the ridge beam and each of the eaves beams, and the upper heat insulation layers of the pair of inclined roof portions are preferably coupled to each other at a boundary portion between the both inclined roof portions on an upper side of the ridge beam when viewed from the roof lateral direction.

[0148] According to this configuration, the upper heat insulation layers of the pair of inclined roof portions are continuously connected without interruption on the upper side of the ridge beam to form one heat insulation line (a line in which a surface exhibiting the heat insulation property between the outdoor side and the outdoor side is viewed from the roof lateral direction). Therefore, it is possible to prevent the heat insulation line from being interrupted on the upper side of the ridge beam (that is, the boundary portion between the pair of inclined roof portions) and the heat insulation property of the building from being impaired.

Examples

Embodiment Construction

[0023]Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view illustrating the vicinity of a roof of a building 1 including a roof panel 100 according to an embodiment of the present invention. Note that, although a vertical direction and a left and right direction (horizontal direction) are illustrated in FIG. 1, the direction is illustrated to describe the roof panel 100 according to the present embodiment and the building 1 including the same, and does not limit the structure, the use mode, and the like of the roof panel and the building according to the present invention. Furthermore, in FIG. 1, as an example, the left side of the plane of drawing is illustrated as the outside of the building 1, and the right side of the plane of drawing is illustrated as the inside of the building 1.

Overall Configuration of Building

[0024]The building 1 includes a building body 10 and a roof 50 constitu...

DESCRIPTIONTechnical Field

[0001] The present invention relates to a roof panel and a building provided with the roof panel.Background Art

[0002] Conventionally, there has been known a roof panel including a roof frame, a heat insulation member disposed in a space in the roof frame, and an airtight moisture-proof sheet covering the heat insulation member on a lower surface of the roof frame (see, for example, Patent Literature 1 below).

[0003] The roof panel is installed across and on an upper side of a plurality of horizontal members extending in a roof lateral direction (a width direction of the roof), such as a ridge beam, a purlin, and an eaves beam. The roof frame used for the roof panel includes a plurality of rafter members extending in a direction orthogonal to the horizontal member and disposed at intervals in the roof lateral direction. Spaces between the plurality of rafter members are filled with the heat insulation member. A lower surface of the heat insulation member is covered with the moisture-proof sheet. A roof board is fixed to an upper surface of the heat insulation member, and a finishing material is fixed to a lower surface of the moisture-proof sheet.CITATION LISTPatent LiteraturePatent Literature 1: JP 2019-90224 ASUMMARY OF INVENTIONProblems to be Solved by the Invention

[0005] In the conventional roof panel disclosed in Patent Literature 1, a lower surface of the heat insulation member (heat insulation layer) is covered with the moisture-proof sheet (roof side airtight layer). For this reason, in winter, entry of high-humidity air in a building into the heat insulation layer is suppressed by the roof side airtight layer, and as a result, dew condensation (so-called winter type dew condensation) in the heat insulation layer is suppressed. However, in summer, high-humidity air outside the building passes through the heat insulation layer of the roof panel and reaches the roof side airtight layer, and in this state, the roof side airtight layer is cooled by the air cooled by an air conditioner, so that dew condensation (so-called summer type dew condensation) occurs in the heat insulation layer. As described above, in the conventional roof panel, although the generation of the winter type dew condensation in the heat insulation layer can be suppressed, the generation of the summer type dew condensation cannot be suppressed. Therefore, it is conceivable to dispose the roof side airtight layer on the upper surface of the heat insulation layer in order to suppress the summer type dew condensation, but in this case, since the roof side airtight layer is cooled by low-temperature outside air in winter, the winter type dew condensation occurs in the heat insulation layer as described above. When dew condensation occurs in the heat insulation layer regardless of whether it is summer type dew condensation or winter type dew condensation, corrosion of the heat insulation layer proceeds to cause a problem that heat insulation performance of the heat insulation layer is deteriorated.

[0006] An object of the present invention is to effectively suppress occurrence of dew condensation in a heat insulation layer of a roof panel regardless of summer type dew condensation and winter type dew condensation.Means for Solving the Problems

[0007] A roof panel according to one aspect of the present invention is a roof panel installed across and on an upper side of a plurality of horizontal members, the plurality of horizontal members extending in a roof lateral direction and arranged at intervals in a roof longitudinal direction orthogonal to the roof lateral direction, the roof panel including: a frame body disposed across the plurality of horizontal members in an installed state of the roof panel; an upper heat insulation layer and a lower heat insulation layer that are supported by the frame body and are disposed side by side, one above another; and a roof side airtight layer interposed between the upper heat insulation layer and the lower heat insulation layer, in which a thickness of the upper heat insulation layer is larger than a thickness of the lower heat insulation layer.BRIEF DESCRIPTION OF DRAWINGS

[0008] FIG. 1 is a vertical cross-sectional view along a roof longitudinal direction illustrating a vicinity of a roof of a building provided with a roof panel according to an embodiment of the present invention.

[0009] FIG. 2 is a perspective view illustrating an inclined roof portion.

[0010] FIG. 3 is an enlarged cross-sectional view illustrating a portion III in FIG. 1 in an enlarged manner.

[0011] FIG. 4 is a vertical cross-sectional view along the roof longitudinal direction illustrating a state immediately before the roof panel is installed on an upper side of a plurality of horizontal members provided in a building body.

[0012] FIG. 5 is an internal cut model in which a part of the roof panel is cut and each layer inside the roof panel is exposed in order from an upper layer.

[0013] FIG. 6 is a perspective view illustrating an extracted frame body of the roof panel.

[0014] FIG. 7 is an extracted perspective view illustrating a frame body, a roof side moisture-proof sheet, and an eaves beam attachment member in the roof panel.

[0015] FIG. 8 is a perspective view illustrating a state in which a purlin attachment member is further attached to the frame body from the state of FIG. 7.

[0016] FIG. 9 is a perspective view illustrating a state in which a lower heat insulation member is further attached to the frame body from the state of FIG. 8.

[0017] FIG. 10 is a perspective view illustrating a state in which an upper heat insulation member is further attached to the frame body from the state of FIG. 9.

[0018] FIG. 11 is a completed perspective view illustrating a state in which a roof board is further attached to the frame body from the state of FIG. 10.

[0019] FIG. 12A is a view corresponding to a partial cross-sectional view of a left end of FIG. 4 and illustrating a first modified embodiment.

[0020] FIG. 12B is a view corresponding to a partial cross-sectional view of a left end of FIG. 4 and illustrating a second modified embodiment.

[0021] FIG. 13A is a view corresponding to a partial cross-sectional view of a left end of FIG. 4 and illustrating a third modified embodiment.

[0022] FIG. 13B is a view corresponding to a partial cross-sectional view of a left end of FIG. 4 and illustrating a fourth modified embodiment.DESCRIPTION OF EMBODIMENTS

[0023] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view illustrating the vicinity of a roof of a building 1 including a roof panel 100 according to an embodiment of the present invention. Note that, although a vertical direction and a left and right direction (horizontal direction) are illustrated in FIG. 1, the direction is illustrated to describe the roof panel 100 according to the present embodiment and the building 1 including the same, and does not limit the structure, the use mode, and the like of the roof panel and the building according to the present invention. Furthermore, in FIG. 1, as an example, the left side of the plane of drawing is illustrated as the outside of the building 1, and the right side of the plane of drawing is illustrated as the inside of the building 1.Overall Configuration of Building

[0024] The building 1 includes a building body 10 and a roof 50 constituted by a plurality of roof panels 100.

[0025] The roof 50 is disposed so as to close the ceiling side of the building body 10 and partitions an outdoor space OS and an indoor space IS. The roof 50 is a so-called gable roof, and has a pair of left and right inclined roof portions 50L and 50R arranged so as to constitute a hypotenuse of an isosceles triangle having a ridge as a vertex when viewed from the end side (front side in a direction perpendicular to the plane of FIG. 1). In FIG. 1, only the left inclined roof portion 50L and the vicinity of the periphery thereof and the vicinity of the upper end portion of the other inclined roof portion 50R are illustrated, and the other portions are omitted. Note that, in the following description, a direction parallel to the ridge of the roof 50 (a direction perpendicular to the plane of FIG. 1) is defined as a roof lateral direction, and a direction orthogonal to the roof lateral direction along the roof surface (in this example, the same direction as a roof inclination direction) is defined as a roof longitudinal direction.

[0026] FIG. 2 is a perspective view illustrating the inclined roof portions 50L and 50R constituting the roof 50. Each of the inclined roof portions 50L and 50R includes a plurality of roof panels 100 arranged in the roof lateral direction. Each roof panel 100 is installed across and on an upper side of a plurality of horizontal members 21 provided on the building body 10. Note that, in FIG. 2, only two roof panels 100 located at both ends in the roof lateral direction are illustrated, and the roof panel 100 located between the two roof panels is not illustrated.

[0027] Referring to FIG. 1, a plurality of tile bars 52 extending in a roof lateral direction (a direction perpendicular to the plane of FIG. 1) and arranged at intervals in a roof longitudinal direction are fixed to an upper surface of each roof panel 100 (an upper surface of a roof board 160 to be described later), and a tile 51 is laid across the adjacent tile bars 52. The upper end portion of each tile 51 is latched to the tile bar 52, and the lower end portion is overlapped and fixed to the upper end portion of the tile 51 adjacent on the lower side from above.Building Body

[0028] The building body 10 includes a roof support structure 20 including the plurality of horizontal members 21 and a side wall portion 30 forming a side surface of the building 1.

[0029] The roof support structure 20 includes a ridge beam 22, a purlin 23, and an eaves beam 24 as the horizontal members 21. The ridge beam 22, the purlin 23, and the eaves beam 24 are made of a wooden long member having a rectangular cross section extending in the roof lateral direction, and are arranged at intervals in the roof longitudinal direction. The ridge beam 22, the purlin 23, and the eaves beam 24 are arranged such that the installation height decreases in this order from the ridge side to the eaves side according to a roof gradient. The eaves beam 24 corresponds to an outermost horizontal member located on the most roof outer side in the roof longitudinal direction. Note that the arrangement of the horizontal members 21 in FIG. 1 is an example, and the number and shape of the horizontal members 21 are not limited thereto. Furthermore, the material of the horizontal member 21 is not limited to wood, and may be, for example, metal.

[0030] Only one ridge beam 22 is provided below the boundary portion between the left and right inclined roof portions 50L and 50R. The purlin 23 and the eaves beam 24 are provided below the left and right inclined roof portions 50L and 50R, respectively. A plurality of the purlins 23 may be provided. A beam 28 located at the same height as the two eaves beams 24 and extending in the roof lateral direction is disposed at the center between the left and right eaves beams 24.

[0031] The left and right eaves beams 24 and the central beam 28 are coupled by a plurality of joists (not illustrated) extending in the left and right direction and arranged at intervals in the roof lateral direction.

[0032] The ridge beam 22 and the purlin 23 are connected to the plurality of beams via a hut bundle (not illustrated). The eaves beam 24 is supported from below by a plurality of pillar members 38 (only one is illustrated in FIG. 1) extending in the vertical direction and arranged at intervals in a roof lateral direction (a direction perpendicular to the plane of FIG. 1). The plurality of pillar members 38 function as a support member of the eaves beam 24 and also function as a framework member of the side wall portion 30 described later.

[0033] As illustrated in FIG. 3, the side wall portion 30 is a vertical wall portion whose upper end portion is connected to the roof 50, and is disposed so as to partition the outdoor space OS and the indoor space IS.

[0034] Specifically, the side wall portion 30 includes an outer wall panel 31, an outer heat insulation layer 32, a base material 33, an inner heat insulation layer 34, a body side moisture-proof sheet 35 as a body side airtight layer 39, and an inner wall panel 36, which are disposed in this order from the outside to the inside in the wall thickness direction.

[0035] The outer wall panel 31 is a member that forms an outer wall surface of the building 1, and extends along the vertical direction. The outer wall panel 31 is disposed at a position slightly spaced apart outward from the outer heat insulation layer 32, and forms a wall side ventilation passage 37 extending in the vertical direction between the outer wall panel and the outer heat insulation layer 32.

[0036] The outer heat insulation layer 32 faces the wall side ventilation passage and is disposed inside the wall side ventilation passage 37. The outer heat insulation layer 32 can enhance heat insulation properties between the outdoor space OS and the indoor space IS. The outer heat insulation layer 32 is made of a hard heat insulation material such as extruded expanded polystyrene. However, the outer heat insulation layer 32 may be made of a fibrous heat insulation material such as cellulose fiber, rock wool, or glass wool.

[0037] The base material 33 is disposed inside the outer wall panel 31 and is made of, for example, plywood. The base material 33 is disposed so as to cover the outer side surface of the eaves beam 24, the outer side surfaces of the plurality of pillar members 38 (only one is illustrated in FIG. 3) supporting the eaves beam 24, and the space S0 between the plurality of pillar members 38 from the outside. Here, the outer side surfaces of the plurality of pillar members 38 and the outer side surface of the eaves beam 24 are flush with each other with a joint therebetween to form an attachment surface of the base material 33. The base material 33 is fixed to the attachment surface with a nail or the like.

[0038] The inner heat insulation layer 34 is a heat insulation material disposed inside the outer heat insulation layer 32, and has a function of enhancing heat insulation properties between the outdoor space OS and the indoor space IS similarly to the outer heat insulation layer 32. The inner heat insulation layer 34 is made of a heat insulation material filled in a space S0 formed between the plurality of pillar members 38 on the lower side of the eaves beam 24, and is made of a fiber-type heat insulation material such as cellulose fiber, rock wool, or glass wool. However, the inner heat insulation layer 34 may be made of a hard heat insulation material such as extruded expanded polystyrene.

[0039] The body side moisture-proof sheet 35 as the body side airtight layer 39 is formed of one or a plurality of resin sheets. The body side moisture-proof sheet 35 is disposed along the vertical direction, and is disposed to cover the inner side surfaces of the plurality of pillar members 38, the inner side surface of the eaves beam 24, and the space S0 between the plurality of pillar members 38 from the inside. The height position of the upper end surface of the body side moisture-proof sheet 35 coincides with the height position of the upper surface of the eaves beam 24. In other words, the upper end surface of the body side moisture-proof sheet 35 is flush with the upper surface of the eaves beam 24. Here, the inner side surfaces of the plurality of pillar members 38 and the inner side surface of the eaves beam 24 are flush with each other with a joint therebetween to form an attachment surface of the body side moisture-proof sheet 35. The body side moisture-proof sheet 35 is fixed to the attachment surface with staples or the like. Thus, the body side moisture-proof sheet 35 can enhance airtightness and moisture-proof properties between the outdoor space OS and the indoor space IS in the side wall portion 30 of the building body 10.

[0040] Note that, in the present embodiment, the eaves beam 24 is made of wood as an example, but even if the eaves beam 24 is made of wood depending on the required airtightness level, the eaves beam 24 itself forms an airtight line (see FIG. 1; details are described below). In this case, the upper end surface of the body side moisture-proof sheet 35 may be located at a height between the upper surface and the lower surface of the eaves beam 24 or at the same height as the lower surface of the eaves beam 24. According to this, the eaves beam 24 itself constitutes a part of the airtight line K, and the body side moisture-proof sheet 35 and a roof side moisture-proof sheet 141 to be described later are connected by the eaves beam 24, whereby the airtight line K (see FIG. 1) extending from the building body 10 side to the roof 50 side is formed.

[0041] The inner wall panel 36 is made of a plate material such as plasterboard, for example, and is disposed such that its inner surface faces an interior space S1. The inner wall panel 36 is disposed inside the body side moisture-proof sheet 35 along the vertical direction.

[0042] An upper end surface of the inner wall panel 36 is connected to a lower surface of a ceiling plate member 25 that partitions the interior space S1 and the attic space S2. The ceiling plate member 25 is supported by a field edge 26 extending in the left and right direction at the lower end of the roof support structure 20 described above. Both end portions of the field edge 26 in the left and right direction are coupled to the inner side surface of the eaves beam 24 via a base tree 40 and a coupling plate member 41.Roof Panel

[0043] Next, details of the roof panel 100 constituting the roof 50 will be described. FIG. 4 is a vertical cross-sectional view taken along the roof longitudinal direction illustrating a state immediately before the roof panel 100 is installed on the upper side of the ridge beam 22, the purlin 23, and the eaves beam 24. As illustrated in this drawing, the roof panel 100 is installed from above at a predetermined installation position above the ridge beam 22, the purlin 23 and the eaves beam 24. As described later, the roof panel 100 is completely installed by fixing an eaves beam attachment member 151 to the upper surface of the eaves beam 24 and fixing a purlin attachment member 150 to the upper surface of the purlin 23. In the following description, unless otherwise specified, the roof panel 100 will be described assuming that the installation of the roof panel 100 is completed (hereinafter, referred to as an installed state).

[0044] FIG. 5 is an internal cut model in which a part of the roof panel 100 is cut to expose each layer 120, 130, 140 inside in order from the upper layer.

[0045] The roof panel 100 includes a frame body 110, a plurality of upper heat insulation members 121 constituting the upper heat insulation layer 120, a plurality of lower heat insulation members 131 constituting the lower heat insulation layer 130, one roof side moisture-proof sheet 141 constituting the roof side airtight layer 140, a purlin attachment member 150, an eaves beam attachment member 151, and a plurality of roof boards 160.

[0046] FIG. 6 is an extracted perspective view illustrating the frame body 110 of the roof panel 100. Referring to FIGS. 5 and 6, the frame body 110 includes a plurality of (four in this example) rafter members 111 extending in the roof longitudinal direction across the ridge beam 22, the purlin 23, and the eaves beam 24 in the installed state of the roof panel 100, and a coupling member 112 coupling the plurality of rafter members 111. The frame body 110 is made of wood, but is not limited thereto, and may be made of metal or resin, for example.

[0047] The plurality of rafter members 111 are disposed at intervals (at equal intervals in the example of FIG. 6) in the roof lateral direction. Each of the rafter members 111 is formed of a long plate member extending in the roof longitudinal direction and having a thickness in the roof lateral direction.

[0048] The coupling member 112 is formed of a long plate member extending in the roof lateral direction. The coupling member 112 is fixed to each of the plurality of rafter members 111 in a state where one side surface in the thickness direction abuts on eaves side end surfaces of the plurality of rafter members 111. The coupling member 112 includes a coupling body 112a extending from the rafter member 111 located at the most one-side end in the roof lateral direction to the rafter member 111 located at the most other-side end, and a protruding plate 112b connected to the coupling body 112a and protruding toward the other side from the rafter member 111 located at the most other-side end. A protruding length L2 of the protruding plate 112b is set to be equal to, for example, an interval L1 between the adjacent rafter members 111. By providing the protruding plates 112b in this manner, when the frame bodies 110 are disposed in the roof lateral direction, the rafter members 111 of the adjacent frame bodies 110 are disposed so as to compensate for the rafter members 111 missing at the protruding end portions of the protruding plates 112b. Therefore, it is possible to prevent the rafter members 111 from being disposed in an overlapping manner (one extra member is arranged) near the boundary portions of the frame bodies 110 adjacent to each other.

[0049] Furthermore, a communication passage 162 (see FIGS. 1 and 3) which is a space partitioned by the plurality of rafter members 111 and communicating with a roof side ventilation passage 161 to be described later is formed between the coupling member 112 and the eaves side end surface of the upper heat insulation layer 120.

[0050] FIG. 7 is an extracted perspective view illustrating the frame body 110, the roof side moisture-proof sheet 141, and the eaves beam attachment member 151 of the roof panel 100. As illustrated in FIGS. 4 and 7 described above, the roof side moisture-proof sheet 141 is made of, for example, one resin sheet.

[0051] As illustrated in FIG. 4, the roof side moisture-proof sheet 141 has a flat sheet portion 141a and a lower extending sheet portion 141b. The flat sheet portion 141a corresponds to an intervening portion interposed between the upper heat insulation layer 120 and the lower heat insulation layer 130, and the lower extending sheet portion 141b corresponds to a non-intervening portion connected to the intervening portion.

[0052] The flat sheet portion 141a has a rectangular sheet shape having the same width as the coupling member 112 of the frame body 110. The flat sheet portion 141a is formed across the ridge beam 22 and the eaves beam 24 when viewed from a direction perpendicular to the roof surface so as to close a space therebetween. As illustrated in FIG. 7, the flat sheet portion 141a is disposed along lower end surfaces of the plurality of rafter members 111 in the frame body 110, and is fixed to the frame body 110 by staples (not illustrated).

[0053] The lower extending sheet portion 141b is connected to an eaves side end edge of the flat sheet portion 141a. The lower extending sheet portion 141b extends downward (vertically lower side in this example) from an extension line of the flat sheet portion 141a. As illustrated in FIG. 4, the lower extending sheet portion 141b extends vertically downward from the eaves side end edge of the flat sheet portion 141a while being sandwiched between the eaves beam attachment member 151 and the lower heat insulation member 131. The lower end surface of the lower extending sheet portion 141b is located at the same height as a lower surface 151c of the eaves beam attachment member 151. In other words, the lower end surface of the lower extending sheet portion 141b is formed to be flush with the lower surface 151c of the eaves beam attachment member 151. Furthermore, the lower end surface placement of the lower extending sheet portion 141b is located slightly lower than the lower end position of the adjacent lower heat insulation member 131. The lower end surface of the lower extending sheet portion 141b abuts on the upper end surface of the body side moisture-proof sheet 35 in the installed state of the roof panel 100 (see FIG. 3). Note that the lower extending sheet portion 141b may be disposed so as to overlap the body side moisture-proof sheet 35 in the thickness direction.

[0054] The eaves beam attachment member 151 is a member for attaching the roof panel 100 to the upper surface of the eaves beam 24. As illustrated in FIG. 7, the eaves beam attachment member 151 is fixed to a place corresponding to the eaves beam 24 on the lower end surface of each of the rafter members 111 by a screw 101. The eaves beam attachment member 151 extends in a direction orthogonal to each of the rafter members 111 when viewed from below.

[0055] Specifically, the eaves beam attachment member 151 is formed of a long member having a triangular prism shape extending in the roof lateral direction. The length of the eaves beam attachment member 151 in the roof lateral direction is set to be equal to the lateral width of the roof side moisture-proof sheet 141, for example.

[0056] As illustrated in FIG. 4, the eaves beam attachment member 151 is disposed facing (adjacent to) the lower extending sheet portion 141b of the roof side moisture-proof sheet 141 in the roof longitudinal direction. The eaves beam attachment member 151 is interposed between the eaves beam 24 and the frame body 110 to hold an inclination angle of each of the rafter members 111 with respect to the horizontal direction (the left and right direction in this example) at a predetermined angle (an angle corresponding to a roof gradient).

[0057] Specifically, the eaves beam attachment member 151 includes: an inclined surface 151a that is inclined so as to be lower from the ridge side toward the eaves side at an angle according to the roof gradient; a vertical end surface 151b that extends downward from an upper end edge of the inclined surface 151a; and a horizontal lower surface 151c that connects a lower end edge of the vertical end surface 151b and a lower end edge of the inclined surface 151a. The inclined surface 151a of the eaves beam attachment member 151 is in contact with the lower end surface of each of the rafter members 111. The lower surface 151c of the eaves beam attachment member 151 is placed on an upper surface of the eaves beam 24. The vertical end surface 151b sandwiches the lower extending sheet portion 141b of the roof side moisture-proof sheet 141 with the lower heat insulation member 131 to fix the lower extending sheet portion 141b.

[0058] FIG. 8 is a perspective view illustrating a state in which the purlin attachment member 150 is further attached to the frame body 110 from the state of FIG. 7. The purlin attachment member 150 is a member for attaching the roof panel 100 to the purlin 23 (see FIG. 4).

[0059] Referring to FIGS. 4 and 8 described above, the purlin attachment member 150 is fixed at a position corresponding to the purlin 23 on the lower end surface of each of the rafter members 111 with the roof side moisture-proof sheet 141 interposed therebetween. For this fixing, for example, a screw 102 (see FIG. 8) is used. The purlin attachment member 150 extends in a direction orthogonal to each of the rafter members 111 when viewed from below.

[0060] The purlin attachment member 150 is interposed between the purlin 23 and the frame body110 to hold an inclination angle of each of the rafter members 111 with respect to the horizontal direction (the left and right direction in this example) at the predetermined angle (an angle corresponding to a roof gradient). A basic configuration of the purlin attachment member 150 is similar to that of the eaves beam attachment member 151. That is, the purlin attachment member 150 includes an inclined surface 150a, a vertical end surface 150b, and a lower surface 150c, the inclined surface 150a abuts on the lower end surface of each of the rafter members 111, and the lower surface 150c is placed on the upper surface of the purlin 23. The vertical end surface 150b abuts on the end face of the lower heat insulation member 131 located on the ridge side to position the lower heat insulation member 131 in the roof longitudinal direction.

[0061] FIG. 9 is a perspective view illustrating a state where the lower heat insulation member 131 is further attached to the frame body 110 from the state of FIG. 8.

[0062] As illustrated in FIGS. 4 and 9, the lower heat insulation member 131 has a rectangular plate shape elongated in the roof longitudinal direction. In the present embodiment, four lower heat insulation members 131 are provided in total, and each of the lower heat insulation members 131 is made of a hard heat insulation material such as extruded expanded polystyrene. However, each lower heat insulation member 131 may be made of a fibrous heat insulation material such as cellulose fiber, rock wool, or glass wool. The four lower heat insulation members 131 are fixed to the frame body 110 with the roof side moisture-proof sheet 141 interposed therebetween. Two lower heat insulation members 131 are provided in each of an eaves side region r1 between the eaves beam attachment member 151 and the purlin attachment member 150 on the lower surface side of the frame body 110 and a ridge side region r2 on the ridge side with respect to the purlin attachment member 150 on the lower surface side of the frame body 110. The eaves side region r1 corresponds to a space between the purlin 23 and the eaves beam 24, and the ridge side region r2 corresponds to a space between the ridge beam 22 and the purlin 23. In each of the regions r1 and r2, the two lower heat insulation members 131 are disposed side by side without a gap in the roof lateral direction. Each lower heat insulation member 131 is fixed to the frame body 110 with the flat sheet portion 141a of the roof side moisture-proof sheet 141 interposed therebetween. For this fixing, for example, a screw 103 is used. The four lower heat insulation members 131 constitute the lower heat insulation layer 130. The lower heat insulation layer 130 has a function of enhancing heat insulation properties between the outdoor space OS and the indoor space IS in the roof 50 (see FIGS. 1 and 3).

[0063] As illustrated in FIG. 4, the lower heat insulation member 131 disposed on the ridge side is disposed so as to expose the ridge side end edge of the flat sheet portion 141a of the roof side moisture-proof sheet 141. This exposed portion constitutes a ridge attachment surface portion 141c for attaching the roof panel 100 to the ridge beam 22. A pedestal member 27 to which the ridge attachment surface portion 141c is fixed is provided on the upper surface of the ridge beam 22. The pedestal member 27 is an elongated member having a substantially trapezoidal cross section and extending over the entire ridge beam 22 in the extending direction, and includes left and right inclined surfaces 27a inclined along the roof gradient, a horizontal upper end surface 27b connecting upper ends of the left and right inclined surfaces 27a, and a lower surface 27c fixed to an upper surface of the ridge beam 22. The left and right inclined surfaces 27a and the horizontal upper end surface 27b are covered with a ridge beam moisture-proof sheet 29. The ridge beam moisture-proof sheet 29 is made of one resin sheet, and is fixed to the left and right inclined surfaces 27a and the horizontal upper end surface 27b of the pedestal member 27 with an adhesive or the like.

[0064] FIG. 10 is a perspective view illustrating a state where the upper heat insulation member 121 is further attached to the upper surface side of the frame body 110 from the state of FIG. 9.

[0065] As illustrated in FIGS. 4 and 10, the upper heat insulation member 121 is formed in a strip plate shape elongated in the roof longitudinal direction. In the present embodiment, eight upper heat insulation members 121 are provided in total. Each of the upper heat insulation members 121 is made of, for example, a hard heat insulation material such as extruded expanded polystyrene. However, each upper heat insulation member 121 may be made of a fiber-based heat insulation material such as cellulose fiber, rock wool, or glass wool.

[0066] The eight upper heat insulation members 121 are disposed so as to fill the spaces 113 extending in the roof longitudinal direction facing the side surfaces of the rafter members 111. Each space 113 is a space opened upward with the flat sheet portion 141a of the roof side moisture-proof sheet 141 as a bottom surface. In each space 113, two upper heat insulation members 121 are disposed side by side without a gap in the roof longitudinal direction. These eight upper heat insulation members 121 are fixed to the frame body 110 by screws 104. The lateral width dimension of each of the upper heat insulation members 121 is set so as to be accommodated in a space formed between the side surfaces of each of the rafter members 111. Furthermore, the dimension of the upper heat insulation member 121 in the roof longitudinal direction is set to such a length that at least the entire space between the ridge beam 22 and the eaves beam 24 is closed when the two upper heat insulation members 121 are arranged without a gap in the roof longitudinal direction. In the example of FIG. 10, the upper heat insulation member 121 on the ridge side is formed longer than the upper heat insulation member 121 on the eaves side in the roof longitudinal direction, but the magnitude relationship of the length is not limited thereto. Furthermore, a thickness T1 (see FIG. 4) of the upper heat insulation member 121 is larger than a thickness T2 of the lower heat insulation member 131. Here, the thickness is a thickness in a direction perpendicular to the roof surface. In FIG. 4, as an example, the thickness T1 of the upper heat insulation member 121 is set to 2 to 3 times the thickness T2 of the lower heat insulation member 131.

[0067] Referring to FIG. 4, the upper heat insulation member 121 located on the ridge side protrudes toward the ridge side from the lower heat insulation member 131 disposed below the upper heat insulation member. The ridge side end surface of the upper heat insulation member 121 is covered with a rectangular plate-shaped heat insulation member 171 (see FIG. 4) extending in the roof lateral direction. The heat insulation member 171 is made of, for example, ethylene-propylene rubber (EPT), and is fixed to the upper heat insulation member 121 with a nail 105 or the like (illustrated only in FIG. 10). As illustrated in FIG. 1, the heat insulation members 171 of the left and right roof panels 100 are disposed so as to abut each other on the upper side of the ridge beam 22 (boundary portion between the left and right roof panels 100).

[0068] Referring to FIG. 4, the upper heat insulation member 121 located on the eaves side has a protrusion 121a (corresponding to a protrusion of the upper heat insulation layer 120) protruding to the eaves side from the lower heat insulation member 131 located below the upper heat insulation member. On the lower surface of the protrusion 121a, the eaves beam attachment member 151 and a heat insulation member 170 are fixed side by side. The heat insulation member 170 is disposed on the eaves side with respect to the eaves beam attachment member 151. The heat insulation member 170 is an elongated member extending in the roof lateral direction, and is made of, for example, ethylene-propylene rubber (EPT).

[0069] As illustrated in FIG. 3, the heat insulation member 170 is formed in a trapezoidal cross-sectional shape so as to fill a space between an upper end surface of the outer heat insulation layer 32 provided on the side wall portion 30 of the building body 10 and a lower surface of a protruding portion of the upper heat insulation member 121. The protruding end surface of the upper heat insulation member 121, the outer surface of the heat insulation member 170, and the outer surface of the outer heat insulation layer 32 are flush with each other to form a vertical surface extending in the vertical direction.

[0070] Furthermore, in the installed state of the roof panel 100, the upper heat insulation layer 120 provided on the roof panel 100 of the left inclined roof portion 50L and the upper heat insulation layer 120 provided on the roof panel 100 of the right inclined roof portion 50R are connected via the heat insulation member 171 on the upper side of the ridge beam 22 (boundary portion between the left and right roof panels 100) (see FIG. 1). The upper heat insulation layers 120 of the connected left and right roof panels 100 form a heat insulation line (not illustrated) so as to surround the entire building outside the airtight line K in cooperation with the outer heat insulation layers 32 (see FIG. 1) provided on the left and right side wall portions 30 described above.

[0071] FIG. 11 is a perspective view illustrating a state in which the roof board 160 is attached to the upper side of the frame body 110 from the state of FIG. 10. In this example, four roof boards 160 are provided. These four roof boards 160 are arranged in two rows and two columns so as to cover the entire upper side of the frame body 110. Each of the roof boards 160 is formed of a rectangular plate material elongated in the roof longitudinal direction, and is disposed in contact with an upper end surface of each of the rafter members 111 of the frame body 110. Each of the roof boards 160 is fixed to the frame body 110 by a nail 106.

[0072] As illustrated in FIG. 3, there is a gap between the lower surface of each of the roof boards 160 and the upper surface of the upper heat insulation member 121. This gap constitutes a roof side ventilation passage 161 extending in the roof longitudinal direction along the rafter member 111. The roof side ventilation passages 161 are formed on the roof panels 100 of the left and right inclined roof portions 50L and 50R, and the left and right roof side ventilation passages 161 communicate with each other on the upper side of the ridge beam 22 (see FIG. 1). A lower end portion of each of the roof side ventilation passages 161 communicates with an upper end portion of the wall side ventilation passage 37 through a space between the plurality of rafter members 111. Accordingly, as indicated by broken line arrows in FIG. 3, it is possible to ventilate high-humidity air containing moisture through the wall side ventilation passage 37 and the roof side ventilation passage 161.Procedure for Assembling Roof Panel

[0073] The configuration of the roof panel 100 and the building 1 including the roof panel 100 has been described above. FIGS. 6 to 10 described above are extracted perspective views of respective members of the roof panel 100, and are also understood as assembly procedure diagrams. Hereinafter, this assembly procedure will be briefly described. When the roof panel 100 is assembled, first, the frame body 110 is prepared (see FIG. 6), and the roof side moisture-proof sheet 141 and the eaves beam attachment member 151 are directly attached to the lower end surface of the prepared frame body 110 (see FIG. 7). At this time, first, the eaves beam attachment member 151 is attached to the frame body 110, and one end portion of the roof side moisture-proof sheet 141 is bent along the vertical end surface 151b (see FIG. 4) of the eaves beam attachment member 151 to form the lower extending sheet portion 141b. After the attachment of the eaves beam attachment member 151 and the roof side moisture-proof sheet 141 is completed, the purlin attachment member 150 is attached to the lower surface of the frame body 110 with the roof side moisture-proof sheet 141 interposed therebetween (see FIG. 8), and the lower heat insulation member 131 is fixed to the lower surface of the flat sheet portion 141a of the roof side moisture-proof sheet 141 (see FIG. 9). In this state, the upper heat insulation member 121 is fitted and fixed in each space 113 facing the side surface of each of the rafter members 111 of the frame body 110 (see FIG. 10). At this time, since the lower side of each space 113 is closed by the flat sheet portion 141a of the roof side moisture-proof sheet 141, the upper heat insulation member 121 does not fall downward. After the upper heat insulation member 121 is fixed, the roof board 160 is attached to the frame body 110 to complete the roof panel 100 (see FIG. 11). Note that the work of attaching the heat insulation member 170, 171 may be performed at an appropriate timing. Furthermore, the assembling procedure of the roof panel 100 described here is an example, and the present invention is not limited thereto.Procedure for Assembling Roof Panel to Building Body

[0074] When the completed roof panel 100 (see FIG. 4) is assembled to the building body 10, the roof panel 100 is fixed to the upper surface of the eaves beam 24, the upper surface of the purlin 23, and the upper surface of the ridge beam moisture-proof sheet 29 with screws or the like. Specifically, after the roof panel 100 is tilted and aligned at an angle corresponding to the roof gradient on the upper side of the ridge beam 22, the purlin 23, and the eaves beam 24, the roof panel 100 is moved downward as indicated by a white arrow in FIG. 4 to be fixed. Then, the work of assembling the roof panel 100 is completed.

[0075] Then, when the assembling of the roof panel 100 is completed, as illustrated in FIG. 3, the lower end surface of the lower extending sheet portion 141b of the roof side moisture-proof sheet 141 (roof side airtight layer 140) and the upper end surface of the body side moisture-proof sheet 35 (body side airtight layer 39) abut on each other. As a result, since the body side airtight layer 39 and the roof side airtight layer 140 are continuously connected, a continuous airtight line K extending from the side wall portion 30 side of the building body 10 to the roof 50 side is formed as illustrated in FIG. 1. The airtight lines K are formed on both left and right sides of the ridge beam 22. The left and right airtight lines K are continuously connected via the ridge beam moisture-proof sheet 29 covering the upper surface of the ridge beam 22.

[0076] Note that the airtight line K is a moisture-proof line that is also used for airtightness and is a line in which a surface on which air circulation between the indoor space IS side and the outdoor space OS side is blocked is viewed from the roof lateral direction. If the airtight line K is interrupted in the middle, the airtightness and the moisture resistance of the building 1 are impaired at the interrupted portion. However, in this example, since the airtight line K is continuously connected, the airtightness of the building 1 can be maintained high.Operation and Effect

[0077] As described above, the roof panel 100 according to the present embodiment includes the frame body 110, the upper heat insulation layer 120 and the lower heat insulation layer 130 that are supported by the frame body 110 and disposed side by side, one above the other, and the roof side airtight layer 140 interposed between the upper heat insulation layer 120 and the lower heat insulation layer 130. Then, the thickness T1 of the upper heat insulation layer 120 is set larger than the thickness T2 of the lower heat insulation layer 130.

[0078] According to the roof panel 100, the upper heat insulation layer 120, the lower heat insulation layer 130, and the roof side airtight layer 140 are supported by one frame body 110 to be unitized. Therefore, a worker can complete the installation work of each layer 120, 130, 140 only by installing the roof panel 100, and the work efficiency can be remarkably improved. That is, in a case where such a unitized roof panel 100 is not used, the worker needs to dispose the roof side airtight layer at a position sandwiched between the heat insulation layers, and the work is very difficult. On the other hand, according to the roof panel 100, since the upper heat insulation layer 120, the lower heat insulation layer 130, and the roof side airtight layer 140 are supported by one frame body 110, and the positional relationship therebetween is fixed in advance, the work becomes easier than the case where these layers 120, 130 and 140 are individually installed.

[0079] Furthermore, since the roof side airtight layer 140 (see FIG. 3) is disposed between the upper heat insulation layer 120 and the lower heat insulation layer 130, it is possible to effectively suppress the summer type dew condensation and the winter type dew condensation in each heat insulation layer 120, 130. That is, in winter, upper heat insulation layer 120 can suppress cooling of roof side airtight layer 140 due to low-temperature outside air. Therefore, even if the high-humidity air in the indoor space IS passes through the lower heat insulation layer 130 and reaches the roof side airtight layer 140, the cooling of the air by the roof side airtight layer 140 is suppressed, so that the generation of dew condensation is also suppressed. Furthermore, in the summer season, the lower heat insulation layer 130 can suppress cooling of the roof side airtight layer 140 by the air in the indoor space IS cooled by the air conditioner. Therefore, even if the high-humidity air from the outdoor space OS passes through the upper heat insulation layer 120 and reaches the roof side airtight layer 140, the cooling of the air by the roof side airtight layer 140 is suppressed, so that the generation of dew condensation is also suppressed.

[0080] Here, the temperature of the low-temperature side space in winter (in this case, the outdoor space OS) decreases to near 0° C., whereas the temperature of the low-temperature side space in summer (In this case, indoor space IS) is at most about 20° C. Therefore, in the winter season, the roof side airtight layer 140 is significantly cooled by the low-temperature air in the outdoor space OS as compared with the summer season. Therefore, in the roof panel 100, by setting the thickness T1 of the upper heat insulation layer 120 (that is, the thickness of the heat insulation layer on the outdoor space OS side) to be larger than the thickness T2 of the lower heat insulation layer 130 (the thickness of the heat insulation layer on the indoor space side), the temperature decrease of the roof side airtight layer 140 in the winter season is sufficiently suppressed. This makes it possible to effectively suppress the occurrence of winter type dew condensation. Therefore, according to the roof panel 100, it is possible to effectively suppress both the winter type dew condensation and the summer type dew condensation while filling measures against the winter type dew condensation.

[0081] Furthermore, in the roof panel 100 according to the present embodiment, the roof side airtight layer 140 is configured to be connected to the body side airtight layer 39 provided in the building body 10 in the installed state (see FIG. 3). When the roof side airtight layer 140 and the body side airtight layer 39 are connected, the above-described airtight line K (see FIG. 1) is formed, so that the worker does not need to perform the work of forming the airtight line K separately from the work of installing the roof panel 100, and the work can be efficiently performed.

[0082] In the roof panel 100 according to the present embodiment, the roof side airtight layer 140 includes, in the installed state, the flat sheet portion 141a (intervening portion) interposed between the upper heat insulation layer 120 and the lower heat insulation layer 130, and the lower extending sheet portion 141b (non-intervening portion) connected to the eaves side end edge of the flat sheet portion 141a, and the lower extending sheet portion 141b is connected to the body side airtight layer 39 in the installed state (see FIG. 3). According to this, the roof side airtight layer 140 and the body side airtight layer 39 provided at a position spaced apart from the roof side airtight layer 140 can be easily connected using the lower extending sheet portion 141b.

[0083] Moreover, in the roof panel 100 according to the present embodiment, the lower extending sheet portion 141b is formed to extend downward from the extension line of the flat sheet portion 141a when viewed from the roof lateral direction (see FIG. 3). According to this, the roof side airtight layer 140 and the body side airtight layer 39 disposed at a position spaced apart from each other on the lower side thereof can be more easily connected using the lower extending sheet portion 141b.

[0084] Furthermore, the roof panel 100 according to the present embodiment includes the eaves beam attachment member 151 that is interposed between the frame body 110 and the eaves beam 24 in the installed state to hold the inclination angle of the plurality of rafter members 111 with respect to the left and right direction (an example of the horizontal direction) at a predetermined angle. The lower surface 151c of the eaves beam attachment member 151 is configured to be horizontally supported by the eaves beam 24 in the installed state of the roof panel 100 (see FIG. 3). Accordingly, when the roof panel 100 is installed, the frame body 110 can be prevented from falling along the roof gradient. Accordingly, installation workability of the roof panel 100 can be improved.

[0085] Moreover, in the roof panel 100 according to the present embodiment, in the installed state, the eaves beam attachment member 151 is disposed so as to face the lower heat insulation layer 130 in the roof longitudinal direction, and the lower extending sheet portion 141b of the roof side moisture-proof sheet 141 is disposed so as to be sandwiched between the eaves beam attachment member 151 and the lower heat insulation layer 130 (see FIG. 3). With such a configuration, the lower extending sheet portion 141b of the roof side moisture-proof sheet 141 is firmly fixed between the eaves beam attachment member 151 and the lower heat insulation layer 130. Therefore, it is possible to reliably connect the roof side airtight layer 140 and the body side airtight layer 39 using the lower extending sheet portion 141b while maintaining the position of the lower extending sheet portion 141b constant.

[0086] Furthermore, in the roof panel 100 according to the present embodiment, the lower end surface (an example of the lower end portion) of the lower extending sheet portion 141b of the roof side moisture-proof sheet 141 is configured to be exposed downward from between the eaves beam attachment member 151 and the lower heat insulation layer 130 and connected to the body side airtight layer 39 (see FIG. 3). According to this, since the lower end surface of the lower extending sheet portion 141b is exposed, the lower end surface of the lower extending sheet portion 141b can be easily connected to the body side airtight layer 39. This facilitates formation of the airtight line K (see FIG. 1) by connection between the roof side airtight layer 140 and the body side airtight layer 39.

[0087] In addition, in the roof panel 100 according to the present embodiment, the lower end surface of the lower extending sheet portion 141b of the roof side moisture-proof sheet 141 is located at the same height as the lower surface 151c of the eaves beam attachment member 151 in the installed state (see FIG. 3). According to this, since the lower end surface of the lower extending sheet portion 141b of the roof side moisture-proof sheet 141 and the lower surface of the eaves beam attachment member 151 are flush with each other, when the eaves beam attachment member 151 is attached to the upper surface of the eaves beam 24, the lower extending sheet portion 141b does not interfere and the work can be easily performed. Furthermore, only by installing the roof panel 100, the lower end surface of the lower extending sheet portion 141b and the upper end surface of the body side airtight layer 39 abut on each other, and the roof side airtight layer 140 and the body side airtight layer 39 are connected. Therefore, the work efficiency can be improved. Furthermore, since it is not necessary to overlap the lower extending sheet portion 141b of the roof side moisture-proof sheet 141 in the thickness direction of the body side airtight layer 39, it is possible to save the length of the lower extending sheet portion 141b and reduce the material cost.

[0088] Furthermore, in the roof panel 100 according to the present embodiment, the upper heat insulation member 121 constituting the upper heat insulation layer 120 is disposed in the space 113 formed by the plurality of rafter members 111 and the roof side moisture-proof sheet 141 in the frame body 110 (see FIG. 10). With such a configuration, when a worker places the upper heat insulation member 121 in the space 113, by attaching the roof side moisture-proof sheet 141 to the frame body 110 in advance, it is possible to prevent the upper heat insulation member 121 from falling off from the space 113. Therefore, workability of attaching the upper heat insulation member 121 to the frame body 110 can be improved.

[0089] Furthermore, the roof panel 100 according to the present embodiment further includes a roof board 160 that abuts on upper end surfaces of the plurality of rafter members 111 in the frame body 110 and covers the upper side of the frame body 110. The upper heat insulation layer 120 is configured to form the roof side ventilation passage 161 extending in the roof longitudinal direction between an upper surface of the upper heat insulation layer and the roof board 160 (see FIG. 3). According to this, the high-humidity air in the roof panel 100 can be ventilated through the roof side ventilation passage 161. Therefore, it is possible to prevent high-humidity air from staying in the roof panel 100 to cause dew condensation.

[0090] Furthermore, in the roof panel 100 according to the present embodiment, the frame body 110 further includes a coupling member 112 that extends in the roof lateral direction and connects eaves side end portions of the plurality of rafter members 111. The coupling member 112 is disposed at a position spaced apart from the protrusion 121a of the upper heat insulation layer 120 toward the eaves side. The communication passage 162 partitioned by the plurality of rafter members 111 and communicating with the roof side ventilation passage 161 is formed between the coupling member 112 and the protrusion 121a of the upper heat insulation layer 120 (see FIG. 3). According to this, it is possible to secure the communication passage 162 to the roof side ventilation passage 161 with a simple configuration without forming a communication hole in each heat insulation layer 120, 130 or the frame body 110. In the example of the present embodiment, the air ventilation passage can be easily configured by communicating the wall side ventilation passage 37 and the roof side ventilation passage 161 using the communication passage 162.

[0091] Furthermore, in the building 1 including the roof panel 100 according to the present embodiment, the body side moisture-proof sheet 35 constituting the body side airtight layer 39 is attached to the interior side surface of the eaves beam 24 and the interior side surface of the pillar member 38 and extends in the vertical direction. The roof side airtight layer 140 constituted by the roof side moisture-proof sheet 141 of the roof panel 100 cooperates with the body side airtight layer 39 to form an airtight line K (see FIG. 1) continuous from the side wall portion 30 side to the roof 50 side when viewed from the roof lateral direction. According to this, the airtight line K is continuously connected from the side wall portion 30 side to the roof 50 side, so that airtightness can be secured even at the connection portion between the side wall portion 30 of the building body 10 and the roof 50. Therefore, the generation of the winter type dew condensation and the summer type dew condensation can be more reliably suppressed.

[0092] Furthermore, in the building 1 including the roof panel 100 according to the present embodiment, the upper heat insulation layer 120 provided on the roof panel 100 has the protrusion 121a protruding to the eaves side (the roof outer side) from the lower heat insulation layer 130 in the roof longitudinal direction, and the protrusion 121a is configured to be located above the outer heat insulation layer 32 provided on the side wall portion 30 in the installed state of the roof panel 100. With such a configuration, the respective heat insulation layers 32 and 120 can be disposed so as to surround the outer side of the airtight line I by the upper heat insulation layer 120 of the roof panel 100 and the outer heat insulation layer 32 of the side wall portion 30 of the building body 10 (see FIG. 1). Therefore, the roof side airtight layer 140 and the body side airtight layer 39 constituting the airtight line I can be suppressed from being cooled by the cold air of the outdoor space OS, and the generation of the winter type dew condensation can be suppressed. Furthermore, the heat insulation property of the entire building 1 can be improved to keep the temperature of the interior space S1 comfortable.

[0093] Furthermore, in the building 1 including the roof panel 100 according to the present embodiment, the wall side ventilation passage 37 extending in the vertical direction is formed between the outer heat insulation layer 32 and the outer wall panel 31 in the side wall portion 30, and the wall side ventilation passage 37 communicates with the roof side ventilation passage 161 in the roof panel 100 through the space between the plurality of rafter members 111 (see FIG. 3). According to this, for example, the high-humidity air leaking from the indoor space IS or the high-humidity air entering the indoor side of the outer wall panel 31 from the outdoor space OS is ventilated through the wall side ventilation passage 37 and the roof side ventilation passage 161 as indicated by the dashed arrow in FIG. 3. Therefore, it is possible to suppress the occurrence of dew condensation in the side wall portion 30.

[0094] In the building 1 including the roof panel 100 according to the present embodiment, the roof side airtight layers 140 of the left and right inclined roof portions 50L and 50R are coupled to each other via the ridge beam moisture-proof sheet 29 on the upper side (boundary portion between both inclined roof portions 50L and 50R) of the ridge beam 22 when viewed from the roof lateral direction (see FIG. 1). According to this, the roof side airtight layers 140 of the pair of inclined roof portions 50L and 50R are continuously connected without interruption on the upper side of the ridge beam 22. Therefore, since the left and right airtight lines K are continuously connected on the upper side of the ridge beam 22, it is possible to prevent the airtightness of the building 1 from being impaired at the boundary portions of both the inclined roof portions 50L and 50R.

[0095] Furthermore, in the building 1 including the roof panel 100 according to the present embodiment, the upper heat insulation layers 120 of the left and right inclined roof portions 50L and 50R are coupled to each other on the upper side (boundary portion between both inclined roof portions 50L and 50R) of the ridge beam 22 when viewed from the roof lateral direction (see FIG. 1). According to this, the upper heat insulation layers 120 of the pair of inclined roof portions 50L and 50R are continuously connected without interruption on the upper side of the ridge beam 22 to form one heat insulation line (not illustrated). Therefore, it is possible to prevent the heat insulation line from being interrupted on the upper side (that is, a boundary portion between the pair of inclined roof portions 50L and 50R) of the ridge beam 22 and the heat insulation property of the building 1 from being impaired.Other Modified Embodiments

[0096] Although the roof panel 100 and the building 1 according to the embodiment of the present invention have been described above, the present invention is not limited thereto, and for example, the following modified embodiments can be adopted. Note that, in the following description of modified embodiments, members having the same configurations as those of the previous embodiments are denoted by the same reference signs.

[0097] (1) FIG. 12A illustrates a first modified embodiment. FIG. 12A is a view corresponding to a partial cross-sectional view of the left end in FIG. 4. In the first modified embodiment, the configuration of the lower extending sheet portion 141b of the roof side moisture-proof sheet 141 is different from that of the previous embodiment. That is, in the present modified embodiment, the lower extending sheet portion 141b protrudes downward from the lower end position of the eaves beam attachment member 151. According to this configuration, in the installed state of the roof panel 100, the lower end portion of the lower extending sheet portion 141b (a part of the roof side airtight layer 140) can be connected (fixed) to the upper end portion of the body side airtight layer 39 in an overlapping manner from the inside. Thus, a sufficient connection margin between the roof side airtight layer 140 and the body side airtight layer 39 can be secured. Therefore, it is possible to prevent the continuity of the airtight line K (see FIG. 1) from being impaired at the connection portion between the roof side airtight layer 140 and the body side airtight layer 39. In addition, it is possible to reliably obtain the same operation and effect as those of the previous embodiment in which the continuity of the airtight line K is secured to effectively suppress both the summer type dew condensation and the winter type dew condensation.

[0098] (2) FIG. 12B illustrates a second modified embodiment. The second modified embodiment is different from the first modified embodiment in that the eaves beam attachment member 151 is configured separately from the roof panel 100 and is fixed to the upper surface of the eaves beam 24 in advance. Also with this configuration, similarly to the first modified embodiment, it is possible to obtain an effect that the airtight line K is formed by connecting the roof side airtight layer 140 and the body side airtight layer 39.

[0099] (3) FIG. 13A illustrates a third modified embodiment. In the third modified embodiment, the configuration of the roof side airtight layer 140 is different from that of the previous embodiment. That is, in the present third modified embodiment, the roof side airtight layer 140 includes a roof side moisture-proof sheet 141 and an eaves beam attachment member 152.

[0100] The roof side moisture-proof sheet 141 does not have the lower extending sheet portion 141b in FIG. 3, and is formed only of the flat sheet portion 141a. The eaves side end surface of the flat sheet portion 141a is connected in contact with a vertical end surface 152b of the eaves beam attachment member 152. In this case, the roof side moisture-proof sheet 141 corresponds to an intervening portion interposed between the upper heat insulation layer 120 and the lower heat insulation layer 130, and the eaves beam attachment member 152 corresponds to a non-intervening portion connected to the intervening portion.

[0101] The eaves beam attachment member 152 has the same shape as the eaves beam attachment member 151 of the previous embodiment, but is made of a different material. That is, the eaves beam attachment member 152 is made of a member exhibiting airtightness, for example, resin or metal. Furthermore, the eaves beam attachment member 152 may be formed by coating a surface of wood with resin or metal.

[0102] An inclined surface 152a, the vertical end surface 152b, and a lower surface 152c of the eaves beam attachment member 152 respectively correspond to the inclined surface 151a, the vertical end surface 151b, and the lower surface 151c of the eaves beam attachment member 151 in the previous embodiment, but are different from those in the previous embodiment in the following points. That is, the eaves beam attachment member 152 is formed such that the lower surface 152c of the eaves beam attachment member abuts not only the upper surface of the eaves beam 24 but also the upper end surface of the body side airtight layer 39 in the installed state of the roof panel 100. By this abutment, the roof side airtight layer 140 including the eaves beam attachment member 152 and the roof side moisture-proof sheet 141 is connected to the body side airtight layer 39. Therefore, it is possible to form the airtight line K by connecting the roof side airtight layer 140 and the body side airtight layer 39 only by installing the roof panel 100. Furthermore, since the eaves beam attachment member 152 constituting the roof side airtight layer 140 has higher rigidity and less positional variation than the sheet-like member, it is possible to reliably connect the roof side airtight layer 140 and the body side airtight layer 39 via the eaves beam attachment member 152. Therefore, similarly to the above embodiment, it is possible to obtain an effect that the airtight line K is formed by connecting the roof side airtight layer 140 and the body side airtight layer 39.

[0103] (4) FIG. 13B illustrates a fourth modified embodiment. The fourth modified embodiment is different from the third modified embodiment in that the eaves beam attachment member 152 is configured separately from the roof panel 100 and is fixed to the upper end surfaces of the eaves beam 24 and the body side moisture-proof sheet 35 in advance. In the present modified embodiment, the body side airtight layer 39 is formed of the eaves beam attachment member 152 and the body side moisture-proof sheet 35. Also with this configuration, it is possible to obtain an effect that the airtight line K is formed by connecting the roof side airtight layer 140 and the body side airtight layer 39 similarly to the above-described third modified embodiment.

[0104] (5) In the above embodiment, the horizontal members 21 (ridge beam 22, purlin 23 and eaves beam 24) provided in the building body 10 are made of wood, but the present invention is not limited thereto, and may be made of a metal member such as a steel frame. In this case, the eaves beam 24 itself forms a part of the body side airtight layer 39 to form the airtight line K. However, moreover, foamed urethane may be sprayed to the inner side surface of the metal eaves beam 24 to form the foamed urethane as a part of the body side airtight layer 39. Note that urethane foam may be sprayed onto the inner side surface of the wooden eaves beam 24 to form the urethane foam as a part of the body side airtight layer 39. Furthermore, as described in the above embodiment, depending on the required airtightness level, even if the eaves beam 24 is made of wood, a part of the airtight line K can be constituted by the eaves beam 24.

[0105] (6) The eaves beam attachment member 151 according to the above embodiment and the eaves beam attachment member 152 according to the third and fourth modified embodiments are formed to have a triangular cross section, but the present invention is not limited thereto. For example, the eaves beam attachment member may be formed to have a trapezoidal cross section obtained by cutting a top portion of a triangle into a flat surface shape. That is, the eaves beam attachment member 151, 152 may have any shape as long as it can hold the inclination angle of the frame body 110 with respect to the horizontal direction at a predetermined angle. Furthermore, the lower surface of the eaves beam attachment member 151, 152 is not necessarily formed in a planar shape, and may be formed to be in line contact with the upper surface of the eaves beam 24 along a line extending in the roof lateral direction.

[0106] (7) In the above embodiment, the eaves beam attachment member 151 is made of wood, but is not limited thereto, and may be made of, for example, a metal fitting formed by bending a sheet metal.

[0107] (8) The eaves beam attachment member 151 in the above embodiment and the eaves beam attachment member 152 in the third and fourth modified embodiments are not limited to one member extending in the roof lateral direction along the horizontal member 21, and may be, for example, a plurality of members arranged at intervals in the roof lateral direction. However, in this case, in order to form the stable airtight line K, it is preferable to directly connect the eaves beam attachment member 151, 152 and the roof side moisture-proof sheet 141, which is the roof side airtight layer 140, to the body side airtight layer 39 as in the above embodiment.

[0108] (9) In the above embodiment, the pedestal member 27 (see FIG. 4) covered with the ridge beam moisture-proof sheet 29 is fixed to the upper surface of the ridge beam 22 in advance, but the present invention is not limited thereto. For example, the pedestal member 27 covered with the ridge beam moisture-proof sheet 29 may be attached to one of the left and right roof panels 100 in FIG. 4 in advance.

[0109] (10) In the above embodiment, the roof side airtight layer 140 is formed of the roof side moisture-proof sheet 141, but is not limited thereto, and may be formed of, for example, a waterproof paint formed by spraying or painting on the surface of the heat insulation member. Furthermore, the method for constructing the roof side airtight layer 140 is not limited to the construction procedure in which the roof side moisture-proof sheet 141 is first attached to the frame body 110 and then the lower heat insulation member 131 is attached as illustrated in FIGS. 7 and 8. For example, the roof side moisture-proof sheet 141 or a waterproof paint or the like as the roof side airtight layer 140 may be provided in advance on the lower heat insulation member 131, and then the lower heat insulation member 131 may be attached to the frame body 110 together with the roof side airtight layer 140. That is, a method for providing the roof side airtight layer 140 between the upper heat insulation layer 120 and the lower heat insulation layer 130 may be any method (and procedure).

[0110] (11) In the above embodiment, after the roof side moisture-proof sheet 141 is fixed to the lower surface of the rafter member 111 in the frame body 110, the lower heat insulation member 131 is fixed to the lower surface of the roof side moisture-proof sheet 141. However, the present invention is not limited to this. For example, after an intermediate heat insulation member (not illustrated) is disposed on the lower surface of the rafter member 111, the roof side moisture-proof sheet 141 may be disposed on the lower surface of the intermediate heat insulation member, and the lower heat insulation member 131 may be fixed to the lower surface of the roof side moisture-proof sheet 141. After the lower heat insulation member 131 is disposed, the upper heat insulation member 121 may be disposed in a space facing the side surface of each of the rafter members 111 (the bottom surface of the space is constituted by the intermediate heat insulation member) as in the above embodiment. In the roof panel 100 (not illustrated) created in this manner, the upper heat insulation layer 120 includes two layers of the upper heat insulation member 121 and the intermediate heat insulation member located above the roof side moisture-proof sheet 141, while the lower heat insulation layer 130 includes only the lower heat insulation member 131 located below the roof side moisture-proof sheet 141 as in the above embodiment. Accordingly, the thickness of the upper heat insulation layer 120 can be set sufficiently larger than the thickness of the lower heat insulation layer 130. Note that the procedure of creating the roof panel 100 in this case is not limited to the above-described procedure.

[0111] (12) In the above embodiment, the roof 50 to which the roof panel 100 is applied is configured by a gable roof, but is not limited thereto, and may be configured by, for example, a side roof, a hip roof, or the like. Furthermore, the roof 50 is not limited to these inclined roofs, and may be formed of, for example, a land roof having no inclination.

[0112] (13) The present invention includes any combination of the foregoing embodiments and the respective modified embodiments.

[0113] Note that the above-described specific embodiments of the present invention mainly include inventions having the following configurations. That is, a roof panel according to a first invention is a roof panel installed across and on an upper side of a plurality of horizontal members, the plurality of horizontal members extending in a roof lateral direction and arranged at intervals in a roof longitudinal direction orthogonal to the roof lateral direction, the roof panel including: a frame body disposed across the plurality of horizontal members in an installed state of the roof panel; an upper heat insulation layer and a lower heat insulation layer that are supported by the frame body and are disposed side by side, one above another; and a roof side airtight layer interposed between the upper heat insulation layer and the lower heat insulation layer, in which a thickness of the upper heat insulation layer is larger than a thickness of the lower heat insulation layer.

[0114] According to this roof panel, the upper heat insulation layer, the lower heat insulation layer, and the roof side airtight layer are supported by one frame body to be unitized. Therefore, a worker can complete the installation work of each layer only by installing the roof panel, and the work efficiency can be remarkably improved. That is, in a case where such a unitized roof panel is not used, the worker needs to form an airtight line by disposing the roof side airtight layer at a location sandwiched by the heat insulation layers, and the work becomes very difficult. On the other hand, according to the roof panel, since the upper heat insulation layer, the lower heat insulation layer, and the roof side airtight layer are supported by the frame body in advance and a positional relationship between the upper heat insulation layer, the lower heat insulation layer, and the roof side airtight layer is fixed, the work becomes easy as compared with the case where these layers are individually installed. In the present specification, the “airtight layer” is defined as a moisture-proof layer that also serves as airtight. Furthermore, the airtight line is defined as a moisture-proof line that is also used for airtightness, the moisture-proof line being a line in which a surface on which air circulation between an indoor space side and an outdoor space side is blocked is viewed from the roof lateral direction.

[0115] Then, since the roof side airtight layer is disposed between the upper heat insulation layer and the lower heat insulation layer, it is possible to effectively suppress summer type dew condensation and winter type dew condensation in each heat insulation layer. That is, in winter, the upper heat insulation layer can suppress cooling of the roof side airtight layer by low-temperature outside air. Therefore, even if the high-humidity air in the building passes through the lower heat insulation layer and reaches the roof side airtight layer, the cooling of the air by the roof side airtight layer is suppressed, so that the generation of dew condensation (winter type dew condensation) is also suppressed. Furthermore, in summer, the lower heat insulation layer can suppress cooling of the roof side airtight layer by the air in the building cooled by an air conditioner. Therefore, even if the high-humidity air outside the building passes through the upper heat insulation layer and reaches the roof side airtight layer, the cooling of the air by the roof side airtight layer is suppressed, so that the generation of dew condensation (summer type dew condensation) is also suppressed.

[0116] Here, the temperature of the low-temperature side space (in this case, the outdoor space) in winter decreases to near 0° C., whereas the temperature of the low-temperature side space (in this case, the indoor space) in summer is at most about 20° C. Therefore, in the winter season, the roof side airtight layer is significantly cooled by the low-temperature air in the outdoor space as compared with the summer season. Therefore, in the roof panel, by setting the thickness of the upper heat insulation layer (that is, the thickness of the heat insulation layer on the outdoor space side) to be larger than the thickness of the lower heat insulation layer (the thickness of the heat insulation layer on the indoor space side), it is possible to sufficiently suppress the cooling (temperature decrease) of the roof side airtight layer in winter. As a result, the generation of the winter type dew condensation can be effectively suppressed. Therefore, according to the roof panel, it is possible to effectively suppress both the winter type dew condensation and the summer type dew condensation while filling measures against the winter type dew condensation.

[0117] A roof panel according to a second invention is the roof panel according to the first invention, in which the roof side airtight layer is preferably connected to a body side airtight layer provided in a building body including the plurality of horizontal members in the installed state.

[0118] According to this configuration, when the worker completes the installation work of the roof panel, the roof side airtight layer provided on the roof panel is connected to the body side airtight layer provided on the building body, and one continuous airtight line from the building body side to the roof side is formed. Therefore, work efficiency associated with installation of the roof panel can be remarkably improved. That is, in the conventional roof panel, the worker needs to perform a lot of work for forming the airtight line separately from the installation work of the roof panel, but according to this configuration, the work man-hours required for forming the airtight line is greatly reduced, so that the work efficiency is improved.

[0119] A roof panel according to a third invention is the roof panel according to the second invention, in which the roof side airtight layer preferably includes, in the installed state, a sheet-like intervening portion that is interposed between the upper heat insulation layer and the lower heat insulation layer and extends in the roof longitudinal direction, and a non-intervening portion that is connected to an edge of the intervening portion on a roof outer side in the roof longitudinal direction, and the non-intervening portion is preferably connected to the body side airtight layer in the installed state.

[0120] According to this configuration, the roof side airtight layer can be easily connected to the body side airtight layer using the non-intervening portion of the roof side airtight layer. Therefore, even when the body side airtight layer is located at a position slightly away from a boundary region between the upper heat insulation layer and the lower heat insulation layer, the roof side airtight layer and the body side airtight layer can be connected using the non-intervening portion provided in the roof side airtight layer. Therefore, both the airtight layers can be reliably connected while increasing the degree of freedom in a relative positional relationship (arrangement position) between the body side airtight layer and each heat insulation layer.

[0121] A roof panel according to a fourth invention is the roof panel according to the third invention, in which the non-intervening portion is preferably formed so as to extend downward from an extension line of the intervening portion as viewed in the roof lateral direction.

[0122] According to this configuration, it is possible to more reliably connect the roof side airtight layer and the body side airtight layer using the non-intervening portion of the roof side airtight layer. That is, the body side airtight layer provided in the building body is usually disposed below the roof side airtight layer. The inventors paid attention to this point, and extended the non-intervening portion of the roof side airtight layer downward from the extension line of the sheet-like intervening portion. As a result, the roof side airtight layer and the body side airtight layer located downward from the roof side airtight layer can be reliably connected by the non-intervening portion.

[0123] A roof panel according to a fifth invention is the roof panel according to the third or fourth invention, in which a roof formed by the roof panel is preferably an inclined roof, the roof panel preferably further includes an attachment member that is interposed between the frame body and an outermost horizontal member that is the horizontal member located on a most roof outer side in the roof longitudinal direction in the installed state to hold an inclination angle of a plurality of rafter members with respect to a horizontal direction at a predetermined angle, and the attachment member is preferably fixed to a portion corresponding to the outermost horizontal member in the frame body, and a lower end portion of the attachment member is preferably horizontally supported by the outermost horizontal member in the installed state.

[0124] According to this configuration, when the roof panel is installed on an upper side of the plurality of horizontal members, the lower end portion of the attachment member fixed to the frame body is horizontally supported from the lower side by the outermost horizontal member. Therefore, when the roof panel is installed, the frame body can be prevented from falling along a roof gradient. Accordingly, installation workability of the roof panel can be improved.

[0125] A roof panel according to a sixth invention is the roof panel according to the fifth invention, in which the non-intervening portion of the roof side airtight layer preferably includes the attachment member.

[0126] According to this configuration, it is possible to reliably connect the roof side airtight layer and the body side airtight layer using the non-intervening portion of the roof side airtight layer. That is, since the attachment member has a function of supporting the frame body on the upper surface of the outermost horizontal member, the attachment member is formed of a member having relatively high rigidity. By using such a member having high rigidity as the non-intervening portion of the roof side airtight layer, it is possible to suppress positional variation of the non-intervening portion as compared with, for example, a case where a resin sheet having flexibility is used as the non-intervening portion. Therefore, when the roof panel is installed, the position of the non-intervening portion does not vary and is maintained constant, so that the connection between the roof side airtight layer and the body side airtight layer using the non-intervening portion can be reliably performed. Furthermore, the cost can be reduced by using the existing attachment member as the non-intervening portion.

[0127] A roof panel according to a seventh invention is the roof panel according to the fifth invention, in which the attachment member is preferably disposed so as to face the lower heat insulation layer in the roof longitudinal direction, the non-intervening portion of the roof side airtight layer is preferably disposed to be sandwiched between the attachment member and the lower heat insulation layer, and a lower end portion of the non-intervening portion of the roof side airtight layer is preferably exposed downward from between the attachment member and the lower heat insulation layer in the installed state, and is preferably connected to the body side airtight layer.

[0128] According to this configuration, in the installed state of the roof panel, the lower end portion of the non-intervening portion of the roof side airtight layer is exposed downward from between the attachment member and the lower heat insulation layer, so that the lower end portion of the non-intervening portion can be easily connected to the body side airtight layer. Furthermore, the non-intervening portion of the roof side airtight layer can be sandwiched and firmly fixed between the attachment member and the lower heat insulation layer. Therefore, when the roof panel is installed, the position of the non-intervening portion of the roof side airtight layer is maintained constant without variation, so that the connection between the roof side airtight layer and the body side airtight layer using the non-intervening portion can be reliably performed.

[0129] A roof panel according to an eighth invention is the roof panel according to the seventh invention, in which a lower end surface of the non-intervening portion of the roof side airtight layer is preferably located at a height same as a lower surface of the attachment member in the installed state.

[0130] According to this configuration, since the lower end surface of the non-intervening portion of the roof side airtight layer and the lower surface of the attachment member are flush with each other, it is possible to improve the attachability when the attachment member is attached to the upper surface of the outermost horizontal member as compared with, for example, a case where the non-intervening portion protrudes downward from the lower surface of the attachment member. Furthermore, in this case, when the roof panel is installed, it is not necessary to overlap the non-intervening portion of the roof side airtight layer with the body side airtight layer, so that the length of the non-intervening portion can be saved and the material cost can be reduced.

[0131] A roof panel according to a ninth invention is the roof panel according to the seventh invention, in which the non-intervening portion of the roof side airtight layer preferably protrudes downward from a lower surface of the attachment member in the installed state.

[0132] According to this configuration, when the roof panel is installed, the portion protruding downward from the lower surface of the attachment member in the non-intervening portion of the roof side airtight layer is overlapped in a thickness direction of the body side airtight layer, so that the roof side airtight layer and the body side airtight layer can be connected to each other while a sufficient connection margin between the both is secured. Therefore, it is possible to prevent the continuity of the airtight line from being impaired at a connection portion between the roof side airtight layer and the body side airtight layer.

[0133] A roof panel according to a tenth invention is the roof panel according to any one of the first to ninth inventions, in which the frame body preferably includes a plurality of rafter members extending in the roof longitudinal direction across the plurality of horizontal members in the installed state and arranged at intervals in the roof lateral direction, the roof side airtight layer is preferably disposed so as to cover a lower surface side of the plurality of rafter members across the plurality of rafter members and is fixed to the frame body, and the upper heat insulation layer is preferably disposed in a space formed by the plurality of rafter members and the roof side airtight layer.

[0134] According to this configuration, the upper heat insulation layer is disposed in the space formed by the plurality of rafter members and the roof side airtight layer. A bottom surface of this space is constituted by the roof side airtight layer. Therefore, when the worker disposes the upper heat insulation layer in the space, the upper heat insulation layer can be prevented from falling off from the space by attaching the roof side airtight layer to the frame body in advance. Accordingly, workability of attaching the upper heat insulation layer to the frame body can be improved.

[0135] A roof panel according to an eleventh invention is the roof panel according to the tenth invention, preferably further including a roof board that abuts on upper end surfaces of the plurality of rafter members and covers an upper side of the frame body, in which the upper heat insulation layer preferably forms a roof side ventilation passage extending in the roof longitudinal direction between an upper surface of the upper heat insulation layer and the roof board.

[0136] According to this configuration, the high-humidity air in the roof panel can be ventilated through the roof side ventilation passage. Therefore, it is possible to prevent high-humidity air from staying in the roof panel to cause dew condensation.

[0137] A roof panel according to a twelfth invention is the roof panel according to the eleventh the invention, in which the upper heat insulation layer preferably includes a protrusion protruding beyond the lower heat insulation layer to a roof outer side in the roof longitudinal direction, the frame body preferably includes a coupling member that extends in the roof lateral direction, couples end portions of the plurality of rafter members on the roof outer side in the roof longitudinal direction, and is disposed at a position spaced apart from the protrusion of the upper heat insulation layer on the roof outer side in the roof longitudinal direction, and a communication passage partitioned by the plurality of rafter members and communicating with the roof side ventilation passage is preferably formed between the coupling member and the protrusion of the upper heat insulation layer.

[0138] According to this configuration, it is possible to secure the communication passage to the roof side ventilation passage with a simple configuration without forming a communication hole in each heat insulation layer or the frame body.

[0139] A building according to a thirteenth invention is a building including: a roof formed by the roof panel according to the first invention; and a building body including the plurality of horizontal members and having a ceiling side covered with the roof, in which the building body includes: an outermost horizontal member that is the horizontal member located on a most roof outer side in the roof longitudinal direction; a side wall portion including a plurality of pillar members connected to a lower surface of the outermost horizontal member as a framework; and a body side airtight layer that is attached to an interior side surface of the outermost horizontal member and an interior side surface of the pillar members and extends in a vertical direction to ensure airtightness between an outdoor space and an indoor space in the side wall portion, and the roof side airtight layer is connected to the body side airtight layer, and cooperates with the body side airtight layer to form an airtight line continuous from a side wall portion side to a roof side when viewed from the roof lateral direction.

[0140] According to this configuration, since the airtight line is continuously connected from the side wall portion side to the roof side, airtightness can be secured even at a connection portion between the side wall portion of the building body and the roof. Therefore, for example, in winter, it is possible to prevent high-humidity air in the indoor space from flowing into the upper heat insulation layer of the roof panel from the connection portion between the side wall portion of the building body and the roof and causing dew condensation. Furthermore, in the summer season, it is possible to prevent high-humidity air existing in the outdoor space from entering the lower heat insulation layer of the roof panel from the connection portion between the side wall portion of the building body and the roof and causing dew condensation.

[0141] A building according to a fourteenth invention is the building according to the thirteenth invention, in which the side wall portion preferably includes an outer heat insulation layer provided on an exterior side of the outermost horizontal member and extending in the vertical direction, the upper heat insulation layer of the roof panel preferably includes a protrusion protruding beyond the lower heat insulation layer to a roof outer side in the roof longitudinal direction, and the protrusion is preferably supported by the outermost horizontal member from below and is preferably located above an upper end portion of the outer heat insulation layer in an installed state of the roof panel.

[0142] According to this configuration, since the protrusion of the upper heat insulation layer is located above the outer heat insulation layer, the heat insulation layer can be disposed so as to surround the outside of the airtight line by the upper heat insulation layer of the roof panel and the outer heat insulation layer of the side wall portion of the building body when viewed from the roof lateral direction. Therefore, it is possible to suppress cooling of the roof side airtight layer and the body side airtight layer constituting the airtight line by cold air of the outdoor space, and to suppress generation of the above-described winter type dew condensation. Furthermore, it is possible to improve the heat insulation property of the entire building and to keep an interior temperature comfortable.

[0143] A building according to a fifteenth invention is the building according to the fourteenth invention, in which the roof panel preferably further includes a roof board that abuts on upper end surfaces of the plurality of rafter members and covers an upper side of the frame body, the upper heat insulation layer of the roof panel preferably forms a roof side ventilation passage extending in the roof longitudinal direction between the upper heat insulation layer of the roof panel and the roof board, the side wall portion preferably further includes an outer wall panel that is disposed on an exterior side of the outer heat insulation layer and forms a wall side ventilation passage extending in the vertical direction between the side wall portion and the outer heat insulation layer, and the wall side ventilation passage preferably communicates with the roof side ventilation passage through a space partitioned by the plurality of rafter members.

[0144] According to this configuration, for example, the high-humidity air leaking from the indoor space is ventilated through the wall side ventilation passage and the roof side ventilation passage. Therefore, the generation of dew condensation in the side wall portion can be suppressed.

[0145] A building according to a sixteenth invention is the building according to any one of the thirteenth to fifteenth inventions, in which the plurality of horizontal members preferably include a ridge beam and a pair of eaves beams disposed on both sides of the ridge beam with the ridge beam interposed between the eaves beams, the roof preferably includes a pair of inclined roof portions disposed on both sides of the ridge beam with the ridge beam interposed between the inclined roof portions and disposed across the ridge beam and each of the eaves beams, and the roof side airtight layers of the pair of inclined roof portions are preferably coupled to each other at a boundary portion between the both inclined roof portions on an upper side of the ridge beam when viewed from the roof lateral direction.

[0146] According to this configuration, the roof side airtight layers of the pair of inclined roof portions are continuously connected without interruption on the upper side of the ridge beam to form one airtight line. Therefore, it is possible to prevent the airtightness from being impaired due to interruption of the airtight line on the upper side of the ridge beam (that is, the boundary portion between the pair of inclined roof portions).

[0147] A building according to a seventeenth invention is the building according to any one of the thirteenth to fifteenth inventions, in which the plurality of horizontal members preferably include a ridge beam and a pair of eaves beams disposed on both sides of the ridge beam with the ridge beam interposed between the eaves beams, the roof preferably includes a pair of inclined roof portions disposed on both sides of the ridge beam with the ridge beam interposed between the inclined roof portions and disposed across the ridge beam and each of the eaves beams, and the upper heat insulation layers of the pair of inclined roof portions are preferably coupled to each other at a boundary portion between the both inclined roof portions on an upper side of the ridge beam when viewed from the roof lateral direction.

[0148] According to this configuration, the upper heat insulation layers of the pair of inclined roof portions are continuously connected without interruption on the upper side of the ridge beam to form one heat insulation line (a line in which a surface exhibiting the heat insulation property between the outdoor side and the outdoor side is viewed from the roof lateral direction). Therefore, it is possible to prevent the heat insulation line from being interrupted on the upper side of the ridge beam (that is, the boundary portion between the pair of inclined roof portions) and the heat insulation property of the building from being impaired.

Examples

Embodiment Construction

[0023]Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view illustrating the vicinity of a roof of a building 1 including a roof panel 100 according to an embodiment of the present invention. Note that, although a vertical direction and a left and right direction (horizontal direction) are illustrated in FIG. 1, the direction is illustrated to describe the roof panel 100 according to the present embodiment and the building 1 including the same, and does not limit the structure, the use mode, and the like of the roof panel and the building according to the present invention. Furthermore, in FIG. 1, as an example, the left side of the plane of drawing is illustrated as the outside of the building 1, and the right side of the plane of drawing is illustrated as the inside of the building 1.

Overall Configuration of Building

[0024]The building 1 includes a building body 10 and a roof 50 constitu...

Claims

1. A roof panel installed across and on an upper side of a plurality of horizontal members, the plurality of horizontal members extending in a roof lateral direction and arranged at intervals in a roof longitudinal direction orthogonal to the roof lateral direction, the roof panel comprising:a frame body disposed across the plurality of horizontal members in an installed state of the roof panel;an upper heat insulation layer and a lower heat insulation layer that are supported by the frame body and are disposed side by side, one above another; anda roof side airtight layer interposed between the upper heat insulation layer and the lower heat insulation layer,wherein a thickness of the upper heat insulation layer is larger than a thickness of the lower heat insulation layer.

2. The roof panel according to claim 1, wherein the roof side airtight layer is connected to a body side airtight layer provided in a building body including the plurality of horizontal members in the installed state.

3. The roof panel according to claim 2, whereinthe roof side airtight layer includes, in the installed state, a sheet-like intervening portion that is interposed between the upper heat insulation layer and the lower heat insulation layer and extends in the roof longitudinal direction, and a non-intervening portion that is connected to an edge of the intervening portion on a roof outer side in the roof longitudinal direction, andthe non-intervening portion is connected to the body side airtight layer in the installed state.

4. The roof panel according to claim 3, wherein the non-intervening portion is formed so as to extend downward from an extension line of the intervening portion as viewed in the roof lateral direction.

5. The roof panel according to claim 3, whereina roof formed by the roof panel is an inclined roof,the roof panel further comprises an attachment member that is interposed between the frame body and an outermost horizontal member that is the horizontal member located on a most roof outer side in the roof longitudinal direction in the installed state to hold an inclination angle of a plurality of rafter members with respect to a horizontal direction at a predetermined angle, andthe attachment member is fixed to a portion corresponding to the outermost horizontal member in the frame body, and a lower end portion of the attachment member is horizontally supported by the outermost horizontal member in the installed state.

6. The roof panel according to claim 5, wherein the non-intervening portion of the roof side airtight layer includes the attachment member.

7. The roof panel according to claim 5, whereinthe attachment member is disposed so as to face the lower heat insulation layer in the roof longitudinal direction,the non-intervening portion of the roof side airtight layer is disposed to be sandwiched between the attachment member and the lower heat insulation layer, anda lower end portion of the non-intervening portion of the roof side airtight layer is exposed downward from between the attachment member and the lower heat insulation layer in the installed state, and is connected to the body side airtight layer.

8. The roof panel according to claim 7, wherein a lower end surface of the non-intervening portion of the roof side airtight layer is located at a height same as a lower surface of the attachment member in the installed state.

9. The roof panel according to claim 7, wherein the non-intervening portion of the roof side airtight layer protrudes downward from a lower surface of the attachment member in the installed state.

10. The roof panel according to claim 1, whereinthe frame body includes a plurality of rafter members extending in the roof longitudinal direction across the plurality of horizontal members in the installed state and arranged at intervals in the roof lateral direction,the roof side airtight layer is disposed so as to cover a lower surface side of the plurality of rafter members across the plurality of rafter members and is fixed to the frame body, andthe upper heat insulation layer is disposed in a space formed by the plurality of rafter members and the roof side airtight layer.

11. The roof panel according to claim 10, further comprising a roof board that abuts on upper end surfaces of the plurality of rafter members and covers an upper side of the frame body.wherein the upper heat insulation layer forms a roof side ventilation passage extending in the roof longitudinal direction between an upper surface of the upper heat insulation layer and the roof board.

12. The roof panel according to claim 11, whereinthe upper heat insulation layer includes a protrusion protruding beyond the lower heat insulation layer to a roof outer side in the roof longitudinal direction,the frame body includes a coupling member that extends in the roof lateral direction, couples end portions of the plurality of rafter members on the roof outer side in the roof longitudinal direction, and is disposed at a position spaced apart from the protrusion of the upper heat insulation layer on the roof outer side in the roof longitudinal direction, anda communication passage partitioned by the plurality of rafter members and communicating with the roof side ventilation passage is formed between the coupling member and the protrusion of the upper heat insulation layer.

13. A building comprising:a roof formed by the roof panel according to claim 1; anda building body including the plurality of horizontal members and having a ceiling side covered with the roof,wherein the building body includes:an outermost horizontal member that is the horizontal member located on a most roof outer side in the roof longitudinal direction;a side wall portion including a plurality of pillar members connected to a lower surface of the outermost horizontal member as a framework; anda body side airtight layer that is attached to an interior side surface of the outermost horizontal member and an interior side surface of the plurality of pillar members and extends in a vertical direction to ensure airtightness between an outdoor space and an indoor space in the side wall portion, andthe roof side airtight layer is connected to the body side airtight layer, and cooperates with the body side airtight layer to form an airtight line continuous from a side wall portion side to a roof side when viewed from the roof lateral direction.

14. The building according to claim 13, whereinthe side wall portion includes an outer beat insulation layer provided on an exterior side of the outermost horizontal member and extending in the vertical direction,the upper heat insulation layer of the roof panel includes a protrusion protruding beyond the lower heat insulation layer to a roof outer side in the roof longitudinal direction, andthe protrusion is supported by the outermost horizontal member from below and is located above an upper end portion of the outer heat insulation layer in an installed state of the roof panel.

15. The building according to claim 14, whereinthe roof panel further includes a roof board that abuts on upper end surfaces of the plurality of rafter members and covers an upper side of the frame body,the upper heat insulation layer of the roof panel forms a roof side ventilation passage extending in the roof longitudinal direction between the upper heat insulation layer of the roof panel and the roof board,the side wall portion further includes an outer wall panel that is disposed on an exterior side of the outer heat insulation layer and forms a wall side ventilation passage extending in the vertical direction between the side wall portion and the outer heat insulation layer, andthe wall side ventilation passage communicates with the roof side ventilation passage through a space partitioned by the plurality of rafter members.

16. The building according to claim 13, whereinthe plurality of horizontal members include a ridge beam and a pair of eaves beams disposed on both sides of the ridge beam with the ridge beam interposed between the eaves beams,the roof includes a pair of inclined roof portions disposed on both sides of the ridge bean with the ridge beam interposed between the inclined roof portions and disposed across the ridge beam and each of the caves beams, andthe roof side airtight layers of the pair of inclined roof portions are coupled to each other at a boundary portion between the both inclined roof portions on an upper side of the ridge beam when viewed from the roof lateral direction.

17. The building according to claim 13, whereinthe plurality of horizontal members include a ridge beam and a pair of eaves beams disposed on both sides of the ridge beam with the ridge beam interposed between the eaves beams,the roof includes a pair of inclined roof portions disposed on both sides of the ridge beam with the ridge beam interposed between the inclined roof portions and disposed across the ridge beam and each of the eaves beams, andthe upper heat insulation layers of the pair of inclined roof portions are coupled to each other at a boundary portion between the both inclined roof portions on an upper side of the ridge beam when viewed from the roof lateral direction.

Images