Building, and construction method for airtight connection member in said building

Abstract

A building (1) is provided with: an upper-floor airtight member (41) provided along the surface direction of an upper-floor wall part (4) at a position overlapping a floor underlying member (22) in plan view; a lower-floor airtight member (51) provided along the surface direction of a lower-floor wall part (5) at a position overlapping a floor member (22) in plan view; and an airtight connection member (100) that extends at least from the upper side to the lower side of the end edge section of the floor member (22) and that is formed continuously and seamlessly so as to connect the upper-floor airtight member (41) and the lower-floor airtight member (51).

Description

Building and method for installing connected airtight members in the building

[0001] The present invention relates to a building and a method for installing a connected airtight member in the building.

[0002] Conventionally, buildings have been known that include a lower floor, an upper floor adjacent to the upper side of the lower floor, a cross member arranged between the upper and lower floors, a floor member of the upper floor having an edge portion supported on the top surface of the cross member, and an upper floor wall portion and a lower floor wall portion that are arranged on either side of the floor member, and that are arranged so as to overlap the edge portion of the floor member in a plan view.

[0003] In this type of building, various airtight structures have been proposed to ensure airtightness from upper floors to lower floors. For example, in the airtight structure shown in Figure 7 of Patent Document 1, dry wood (meaning wood with a moisture content of 20% or less) is used for the cross members, making the cross members airtight members, and airtight film is placed along the interior sides of the lower floor walls and upper floor walls. The airtight film covering the lower floor walls is fastened to the interior sides of the cross members using a clamping member, and the airtight film covering the upper floor walls is fastened to the top surfaces of the floor members using airtight tape or the like.

[0004] However, in the airtight structure of Patent Document 1 mentioned above, the edge of the floor member is interposed between the airtight sheet covering the upper floor wall (upper floor airtight member) and the airtight sheet covering the lower floor wall (lower floor airtight member), which creates the problem that the continuity of the airtight line (the line when the airtight surface is viewed from the side) is impaired at the edge of this floor member.

[0005] Japanese Patent Application Laid-Open No. 2004-225420

[0006] The object of the present invention has been made to solve the above-mentioned problems, and is to ensure the continuity of the airtight line extending from the upper floor wall portion to the lower floor wall portion in a building comprising a cross member arranged between the upper and lower floors, a floor member on the upper floor having an edge portion supported on the upper surface of the cross member, and an upper floor wall portion and a lower floor wall portion arranged on the upper floor side and the lower floor side, respectively, sandwiched between the floor member and arranged so as to overlap the edge portion of the floor member in a plan view.

[0007] A building according to one aspect of the present invention comprises a lower floor and an upper floor adjacent to the upper side of the lower floor, and is equipped with: a cross member arranged between the upper and lower floors; a floor member of the upper floor having an edge portion supported on the upper surface of the cross member; an upper floor wall portion and a lower floor wall portion arranged on the upper floor side and the lower floor side, respectively, sandwiching the floor member and overlapping the edge portion of the floor member in a planar view; an upper floor airtight member arranged along the surface direction of the upper floor wall portion at a position overlapping the floor member in a planar view; a lower floor airtight member arranged along the surface direction of the lower floor wall portion at a position overlapping the floor member in a planar view; and a connecting airtight member formed continuously and seamlessly, extending at least from above to below the edge portion of the floor member, so as to connect the upper floor airtight member and the lower floor airtight member.

[0008] A method for installing connecting airtight members in a building according to another aspect of the present invention preferably includes the following steps: a preparation step for preparing the building configuration having the cross member, the upper floor wall portion, the lower floor wall portion, the upper floor airtight member, the lower floor airtight member, and the connecting airtight member; a support fixing step for fixing joist supports that support the longitudinal ends of the joists that support the floor members to the indoor side of the cross member, sandwiching the lower floor airtight members therebetween; a joist installation step for supporting the longitudinal ends of the joists with the joist supports; and a floor member installation step for installing the floor members on the joists and the cross member so that the edge portions of the floor members are covered by the covering portion.

[0009] A method for installing connecting airtight members in a building according to another aspect of the present invention preferably includes the following steps: a preparation step for preparing the building configuration having the cross member, the upper floor wall portion, the lower floor wall portion, the upper floor airtight member, the lower floor airtight member, and the connecting airtight member; a support fixing step for fixing joist supports for supporting the ends of the joists that support the floor members to a portion of the indoor side of the cross member that is lower than the connecting airtight members; a cutting step for cutting out portions of the lower floor airtight members that correspond to the joist supports prior to the support fixing step; a joist installation step for supporting the longitudinal ends of the joists on the joist supports; and a floor member installation step for installing the floor members on the joists and the cross member so that the edge portions of the floor members are covered by the covering portion.

[0010] A method for installing a connecting airtight member in a building according to another aspect of the present invention, wherein the lower floor airtight member has a lower floor airtight main body made of an airtight sheet and a urethane foam layer connected to an upper end of the lower floor airtight main body, and the method includes a preparation step of preparing a structure of the building having the cross member, the upper floor wall portion, the lower floor wall portion, the upper floor airtight member, the lower floor airtight main body portion of the lower floor airtight member, and the connecting airtight member; a support fixing step of fixing joist supports for supporting ends of joists that support the floor members to parts of the indoor side of the cross member that are below the connecting airtight member; and a support step of fixing longitudinal ends of the joists to the joist supports. a lower floor airtightness step of fixing the lower floor airtight main body portion to the lower floor wall portion so that the upper end position of the lower floor airtight main body portion of the lower floor airtight member is located lower than the joist support; a first connection step of connecting the lower end of the upper floor airtight member to the upper connection portion of the connecting airtight member; a second connection step of forming a urethane foam layer by spraying urethane foam so that the upper end of the lower floor airtight main body portion and the lower connection portion of the connecting airtight member are connected; and a floor member installation step of installing the floor members on the joists and cross members so that the edge portions of the floor members are covered by the covering portions.

[0011] FIG. 1 is an enlarged vertical cross-sectional view showing a boundary between an upper floor and a lower floor of a building in the first embodiment. FIG. 2 is a perspective view showing a joist support attached to the indoor side of a cross member. FIG. 3 is an enlarged view showing an arrangement portion of a connecting airtight member in FIG. 1. FIG. 4 is an exploded perspective view for explaining an assembly structure of the connecting airtight member. FIG. 5 is a flowchart showing an example of a method for installing a connecting airtight member. FIG. 6 is a view corresponding to FIG. 1 showing a second embodiment. FIG. 7 is a view corresponding to FIG. 3 showing the second embodiment. FIG. 8 is a view corresponding to FIG. 5 showing the second embodiment. FIG. 9 is a view corresponding to FIG. 1 showing a third embodiment. FIG. 10 is a view corresponding to FIG. 3 showing the third embodiment. FIG. 11 is a view corresponding to FIG. 5 showing the third embodiment. FIG. 12 is a view corresponding to FIG. 4 showing the fourth embodiment. FIG. 13 is a perspective view showing a column airtight member in the fourth embodiment.

[0012] (Embodiment 1) Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is an enlarged longitudinal cross-sectional view showing a boundary between an upper floor 1U and a lower floor 1L in a side wall portion of a building 1 according to one embodiment of the present invention. In the following description, the left-right direction in FIG. 1 is defined as the width direction of the building, and the direction perpendicular to the paper surface is defined as the depth direction of the building. Note that these directions are defined for convenience in describing the structure of the building 1 according to the embodiment of the present invention, and do not limit the configuration of the building 1. Furthermore, in FIG. 1, as an example, the left side of the paper surface is illustrated as the indoor side, and the right side of the paper surface is illustrated as the outdoor side.

[0013] 1, the building 1 is a two-story wooden building having an upper floor 1U (the second floor in this example) and a lower floor 1L (the first floor in this example). Note that the building 1 is not limited to being two stories high, and may be, for example, three or more stories high.

[0014] The building 1 comprises a cross member 50 arranged between the upper floor 1U and the lower floor 1L and extending in the depth direction of the building, a floor substructure 22 (an example of a floor member) that divides the upper floor 1U and the lower floor 1L into upper and lower sections, a plurality of joists 7 (only one is shown in Figure 1) that support the floor substructure 22 from below, an upper floor wall portion 4 and a lower floor wall portion 5 that are arranged on the upper floor side and the lower floor side, respectively, with the edge of the floor substructure 22 sandwiched between them, and an exterior wall portion 6 that is located on the outdoor side of the upper floor wall portion 4 and the lower floor wall portion 5.

[0015] The cross member 50 is a rectangular timber extending in the depth direction of the building. The cross member 50 is connected via multiple columns to an upper cross member (so-called eaves beam) (not shown) that extends in the depth direction of the building and is provided at the upper end of the upper-floor wall 4. As shown in FIG. 4 (described later), the multiple columns include a pair of main columns 18 (only one of which is shown in FIG. 4 ) connected to both end surfaces of the cross member 50 in the extension direction, and multiple upper-floor intermediate columns 43 (only two of which are shown in FIG. 4 ) arranged between the pair of main columns 18 above the cross member 50. The upper-floor intermediate columns 43 are formed as studs or half columns. The lower ends of the upper-floor intermediate columns 43 are formed with notches 43a that accommodate the connecting airtight member 100 (described later) (more specifically, the outer surface of the covering portion 101 of the connecting airtight member 100). The notches 43a are formed in a rectangular shape that opens to the interior when viewed from the depth direction of the building. A plurality of engagement grooves 50a (only two are shown in FIG. 4 ) are formed on the upper surface of the cross member 50, which respectively engage with the lower end of each upper floor intermediate column 43. Each engagement groove 50a extends in a direction perpendicular to the extension direction of the cross member 50 (the width direction of the building) and has a U-shaped cross section that opens upward.

[0016] The cross member 50 is connected via a plurality of pillar members to a lower cross member (so-called base) (not shown) that is provided at the lower end of the lower floor wall portion 5 and extends in the depth direction of the building. The plurality of pillar members includes the pair of main pillars 18 and a plurality of lower floor intermediate pillars 53 (only two are shown in FIG. 4 ) that are arranged below the cross member 50 and between the pair of main pillars 18. The lower floor intermediate pillars 53 are composed of so-called partition pillars or half pillars.

[0017] Returning to Figure 1, the underfloor material 22 is made of a building material such as plywood. A floor finishing material 21 is fixed to the upper surface of the underfloor material 22. The floor finishing material 21 is a so-called flooring material, and is fixed to the upper surface of the underfloor material 22 with adhesive, nails, etc. The outer edge position of the floor finishing material 21 coincides with the lower end position of the upper floor interior panel 15 in a plan view. The edge portion (the end portion on the outer edge side) of the underfloor material 22 protrudes outside beyond the outer edge position of the floor finishing material 21 and is supported on the upper surface of the cross member 50.

[0018] The joists 7 are made of rectangular timbers extending in the width direction of the building (left-right direction in Fig. 1 ) and are spaced apart from one another in the depth direction of the building (perpendicular to the plane of the paper in Fig. 1 ). Both longitudinal ends of each joist 7 (only one end is shown in Fig. 1 ) are connected to the indoor side of the cross member 50 via joist supports 8.

[0019] 2 is a perspective view showing a joist support 8 attached to the indoor side of a cross member 50. As shown in this figure, the joist support 8 has a support body 81 with a U-shaped cross section that opens upward, and a pair of mounting plates 82 connected to both end edges of the support body 81. The support body 81 is fixed to the indoor side of the cross member 50 with mounting screws (not shown) that pass through the pair of mounting plates 82. Each joist 7 is positioned so that its longitudinal end engages with the inside of the support body 81 of the joist support 8. Both end portions of each joist 7 are connected to the cross member 50 via the joist support 8.

[0020] Returning to Figure 1, below the plurality of floor joists 7, there are arranged a ceiling panel 9 that forms the ceiling surface of the lower floor 1L, and a plurality of joists 10 (only one of which is shown in Figure 1).

[0021] Each of the multiple siding members 10 is made of rectangular timbers extending widthwise (left-right in FIG. 1 ) and is spaced apart from one another in the depthwise direction (perpendicular to the plane of FIG. 1 ). Each siding member 10 is supported by a corresponding joist 7 via a hanging beam (not shown). The ceiling panel 9 is fixed to the underside of each siding member 10.

[0022] The edge (outer edge) of the ceiling panel 9 is sandwiched between the upper end surface of the lower floor interior panel 16 and the lower end surface of the base panel 11 fixed to the indoor side of the base timber 12. The base timber 12 is a square timber with a rectangular cross section that extends in the depth direction of the building and is fixed to the lower end of the indoor side of the cross member 50. The upper surface of the base timber 12 is covered by a base panel 13 that is arranged horizontally along the depth direction of the building. The lower end surface of a vertically arranged base panel 14 is connected to the outdoor outer end of the upper surface of the base panel 13. Note that the base panels 13, 14 are not necessarily required, and the building 1 may not have the base panels 13, 14.

[0023] The building 1 has an attic space O located between the underfloor material 22 and the ceiling panel 9. The attic space O contains an attic insulation layer 30. The attic insulation layer 30 includes a first attic insulation material 31 and a second attic insulation material 32. In this example, the first attic insulation material 31 and the second attic insulation material 32 are made of fiber-based insulation materials such as cellulose fiber, rock wool, and glass wool, but are not limited to these and may be made of hard insulation materials such as extruded polystyrene foam.

[0024] The first ceiling insulation material 31 is arranged adjacent to the indoor side of the base panel 11. The lower end of the first ceiling insulation material 31 abuts the upper surface of the joist 10. The upper end of the first ceiling insulation material 31 is located at the same height as the upper surface of the base panel 13 and is connected to the lower end of the second ceiling insulation material 32. Note that the base panel 13 is not necessarily required, and the building 1 may not have the base panel 13. The second ceiling insulation material 32 is arranged adjacent to the lower floor airtight member 51 described below, which covers the indoor side of the cross member 50. The lower end of the second ceiling insulation material 32 abuts the upper surface of the base panel 13. The upper end of the second ceiling insulation material 32 abuts the lower surface of the floor base material 22.

[0025] [Configuration of Upper Floor Wall Portion] The upper floor wall portion 4 has an upper floor wall framework portion 4F, an indoor side insulating layer 42, an upper floor airtight member 41, and an upper floor interior panel 15.

[0026] The upper floor wall skeleton portion 4F includes the above-mentioned upper end cross member (so-called eaves beam, not shown) located at the upper end of the upper floor wall portion 4, and a plurality of column members (in this example, main column 18 and upper floor intermediate column 43, see Figure 4) that connect the upper end cross member to the cross member 50.

[0027] The indoor-side insulation layer 42 is composed of a plurality of insulation materials arranged in the spaces between the plurality of column members. The lower end of the indoor-side insulation layer 42 abuts against the connecting airtight member 100 (described below) that covers the outer edge of the underfloor material 22 (more specifically, the upper surface of the covering portion 101 of the connecting airtight member 100). The outdoor side of the indoor-side insulation layer 42 abuts against the base material 63 of the exterior wall portion 6. In this example, the insulation materials constituting the indoor-side insulation layer 42 are composed of the fiber-based insulation material, but are not limited to this and may be composed of a hard insulation material such as extruded polystyrene foam.

[0028] The upper floor airtight member 41 is composed of, for example, a single airtight sheet. The upper floor airtight member 41 is provided along the surface direction of the upper floor wall portion 4 at a position overlapping the floor underlayment material 22 in a plan view. The upper floor airtight member 41 is formed over the entire upper floor wall portion 4 when viewed from the indoor side. The upper floor airtight member 41 is fixed to the indoor side of the upper floor wall framework portion 4F with staples, tape, etc. The material of the airtight sheet that constitutes the upper floor airtight member 41 is not particularly limited, and various synthetic resin sheets such as polyethylene and polypropylene can be used.

[0029] The upper floor interior panel 15 is made of a plate material such as gypsum board, and is arranged so that its inner surface faces the indoor space of the upper floor 1U. The upper floor interior panel 15 is arranged so that it is aligned in the vertical direction on the indoor side of the upper floor airtight member 41. The upper end surface of the upper floor interior panel 15 abuts against the underside of the ceiling panel (not shown) of the upper floor 1U. The lower end surface of the upper floor interior panel 15 abuts against the upper surface of the edge portion (end portion on the outer edge side) of the floor finishing material 21. The outdoor side of the lower end of the upper floor interior panel 15 is fixed to a base wood 17 fixed to the upper surface of the floor underlayment 22.

[0030] [Configuration of Lower Floor Wall] The lower floor wall 5 has a lower floor wall framework 5F, an indoor side insulating layer 52, a lower floor airtight member 51, and a lower floor interior panel 16.

[0031] The lower floor wall skeleton 5F includes the cross member 50 extending in the depth direction of the building at the upper end of the lower floor wall 5, and a plurality of column members (in this example, the main column 18 and the lower floor intermediate column 53; see Figure 4) that connect the cross member 50 to the above-mentioned lower end cross member (the so-called base; not shown).

[0032] The indoor insulation layer 52 is made up of a plurality of insulation materials respectively arranged in the spaces between the plurality of pillar members. In this example, the insulation materials are made up of the fiber-based insulation material, but this is not limited thereto and may be made up of a hard insulation material such as extruded polystyrene foam.

[0033] The lower floor airtight member 51 is composed of, for example, a single airtight sheet. The lower floor airtight member 51 is provided along the surface direction of the lower floor wall portion 5 at a position overlapping the floor underlayment material 22 in a plan view. The lower floor airtight member 51 is formed over the entire lower floor wall portion 5 when viewed from the indoor side. The lower floor airtight member 51 is fixed to the indoor side of the lower floor wall framework portion 5F with staples, tape, etc. The material of the airtight sheet that constitutes the lower floor airtight member 51 is not particularly limited, and various synthetic resin sheets such as polyethylene and polypropylene can be used.

[0034] The lower floor interior panel 16 is made of a plate material such as gypsum board, and is arranged so that its inner surface faces the interior space of the lower floor 1L. The lower floor interior panel 16 is arranged so that it is aligned vertically on the indoor side of the lower floor airtight member 51. The upper end surface of the lower floor interior panel 16 abuts against the underside of the ceiling panel 9 of the lower floor 1L, as described above. The lower end surface of the lower floor interior panel 16 abuts against the upper surface of the edge of the floor finishing material (not shown) of the lower floor 1L. The outdoor side of the lower end of the lower floor interior panel 16 is fixed to a base wood (not shown) fixed to the upper surface of the floor underlayment material (not shown) of the lower floor 1L.

[0035] [Configuration of the exterior wall section] The exterior wall section 6 is located on the outdoor side of the upper floor wall section 4 and the lower floor wall section 5, and extends continuously in the vertical direction from the upper floor 1U to the lower floor 1L. The exterior wall section 6 has an exterior wall panel 61, an outdoor side insulation layer 62, and a base material 63, which are arranged in this order from the outdoor side toward the indoor side.

[0036] The exterior wall panel 61 is a member that forms the exterior wall surface of the building 1 and extends in the vertical direction.

[0037] The outdoor insulation layer 62 is disposed on the indoor side of the exterior wall panel 61 with a small gap between them. The outdoor insulation layer 62 can improve the thermal insulation performance in the direction from the inside to the outside of the building (in the example of Figure 1, the width direction of the building). The outdoor insulation layer 62 is made of a hard insulation material such as extruded polystyrene foam. However, the outdoor insulation layer 62 may also be made of the above-mentioned fiber-based insulation material.

[0038] The base material 63 is made of plywood or the like and is fixed to the indoor side surfaces of the upper floor wall framework 4F and the lower floor wall framework 5F using nails or the like. The outdoor side surface of the base material 63 is abutted against and fixed to the outdoor side surface of the base material 63.

[0039] [Regarding the airtight structure of the building] In the building 1, the upper floor airtight members 41 provided on the upper floor wall portions 4 and the lower floor airtight members 51 provided on the lower floor wall portions 5 are arranged to overlap the edge portions of the underfloor material 22 in a plan view, which may impair the continuity of the airtight line extending from the upper floor wall portions 4 to the lower floor wall portions 5 at the edge portions of the underfloor material 22. To avoid this problem, the building 1 of this embodiment is provided with a connecting airtight member 100 that connects the upper floor airtight member 41 and the lower floor airtight member 51.

[0040] [Configuration of the linked airtight member] The linked airtight member 100 will be described in detail with reference to Figures 3 and 4. Figure 3 is an enlarged view of the location of the linked airtight member 100 in Figure 1, and Figure 4 is an exploded perspective view for explaining the assembly structure of the linked airtight member 100. Note that in Figure 3, the ceiling insulation layer 30 is omitted for ease of viewing.

[0041] As shown in Fig. 3, the connecting airtight member 100 extends from the upper side to the lower side of the edge portion (the end portion on the outer edge side) of the underfloor material 22, and is connected to the upper floor airtight member 41 and the lower floor airtight member 51. The connecting airtight member 100 is composed of a single airtight sheet that is formed continuously and seamlessly. The material of the airtight sheet is not particularly limited, and various synthetic resin sheets such as polyethylene and polypropylene can be used.

[0042] Specifically, the linked airtight member 100 has a covering portion 101 , an upper connecting portion 102 , and a lower connecting portion 103 .

[0043] The covering portion 101 extends in the depth direction of the building and has a U-shaped cross section that opens to the indoor side. The covering portion 101 engages (fits) with the edge portion of the floor finishing material 21 from the outdoor side.

[0044] The upper connection portion 102 is composed of a rectangular plate portion connected along the entire upper edge of the indoor side of the covering portion 101 (see FIG. 4). The upper connection portion 102 extends upward from the indoor upper edge of the covering portion 101 and overlaps the upper floor airtight member 41 from the outdoor side (see FIG. 3). The upper connection portion 102 is connected to the upper floor airtight member 41 in a breathable manner using airtight tape (not shown). The airtight tape may have an adhesive surface on only one side or on both sides. The airtight tape with an adhesive surface on one side is arranged, for example, to cover the boundary between the lower edge of the upper floor airtight member 41 and the indoor side of the upper connection portion 102. The airtight tape with adhesive surfaces on both sides is arranged, for example, at the overlapping surface between the upper floor airtight member 41 and the upper connection portion 102.

[0045] The lower connection portion 103 is a rectangular plate portion connected along the entire lower edge of the indoor side of the covering portion 101 (see FIG. 4). The lower connection portion 103 extends downward from the indoor lower edge of the covering portion 101 and overlaps the lower floor airtight member 51 from the outdoor side (see FIG. 3). The lower connection portion 103 is connected to the lower floor airtight member 51 in a non-breathable manner using airtight tape (not shown). The airtight tape may have an adhesive surface on only one side or on both sides. The airtight tape with an adhesive surface on one side is arranged, for example, to cover the boundary between the upper edge of the lower floor airtight member 51 and the indoor side of the lower connection portion 103. The airtight tape with adhesive surfaces on both sides is arranged, for example, at the overlapping surface between the lower floor airtight member 51 and the lower connection portion 103.

[0046] [Installation Direction of Linked Airtight Member] Fig. 5 is a flowchart showing an example of an installation method of the linked airtight member 100. The installation method of the linked airtight member 100 will be described below with reference to the flow chart of Fig. 5 and the vertical cross-sectional view of Fig. 1 as appropriate.

[0047] The construction method includes a preparation step SA0, a connecting airtight member assembly step SA1, an indoor-side insulation layer arrangement step SA2, an upper floor airtight step SA3, a first connection step SA4, a lower floor airtight step SA5, a second connection step SA6, a support fixture fixing step SA7, a joist installation step SA8, and a floor member installation step SA9. In this example, these steps SA0 to SA9 are performed in this order, but the order of execution is not limited to this, and the order of execution may be changed as appropriate within the physically possible range.

[0048] In the preparation step SA0, the structure of the building 1 is prepared (constructed) including the cross members 50, the upper floor wall portions 4, the lower floor wall portions 5, the upper floor airtight members 41, the lower floor airtight members 51, and the connecting airtight members 100. In other words, the preparation step SA0 is a step in which the construction of these members is completed in advance.

[0049] In the connecting airtight member assembling step SA1, the connecting airtight member 100 is assembled to an upper corner on the indoor side of the cross member 50 (see FIG. 1 ). Specifically, as shown in FIG. 1 , the connecting airtight member 100 is installed on the upper surface of the cross member 50 so that its covering portion 101 opens to the indoor side. At this time, two orthogonal surfaces formed by the lower surface of the covering portion 101 of the connecting airtight member 100 and the outdoor side surface of the lower connection portion 103 are engaged with a corner on the upper indoor side of the cross member 50 (upper left in FIG. 1 ). That is, the lower surface of the covering portion 101 is abutted against the upper surface of the cross member 50, and the outdoor side surface of the lower connection portion 103 is abutted against the indoor side surface of the cross member 50. This completes the assembly of the connecting airtight member 100 to the cross member 50.

[0050] In the indoor-side insulation layer placement step SA2, the insulation materials that make up the indoor-side insulation layer 42 of the upper floor 1U are placed in the spaces between the column members of the upper floor wall frame 4F. Also, the insulation materials that make up the indoor-side insulation layer 52 of the lower floor 1L are placed in the spaces between the column members of the lower floor wall frame 5F.

[0051] In the upper floor airtightness step SA3, the upper floor airtight member 41 is arranged along the surface direction of the upper floor wall portion 4 (in other words, parallel to the wall surface of the upper floor wall portion 4). At this time, the position of the upper floor airtight member 41 is adjusted so that the lower end of the upper floor airtight member 41 overlaps the upper connection portion 102 of the connecting airtight member 100 from the indoor side (an example of the inside / outside direction of the building). Then, the upper floor airtight member 41 is fixed to the indoor side of the upper floor wall framework portion 4F using staples, tape, etc.

[0052] In the first connecting step SA4, the lower end of the upper floor airtight member 41 and the upper connecting portion 102 of the connecting airtight member 100 are connected in an airtight manner using airtight tape. The location where the airtight tape is attached has already been described.

[0053] In the lower floor airtightness step SA5, the lower floor airtight member 51 is positioned along the surface direction of the lower floor wall portion 5 (in other words, parallel to the wall surface of the lower floor wall portion 5). At this time, the position of the lower floor airtight member 51 is adjusted so that the upper end of the lower floor airtight member 51 overlaps the lower connection portion 103 of the connecting airtight member 100 from the indoor side (an example of the inside / outside direction of the building). The lower floor airtight member 51 is then fixed to the indoor side of the lower floor wall framework portion 5F using staples, tape, etc.

[0054] In the second connecting step SA6, the upper end of the lower floor airtight member 51 and the lower connecting portion 103 of the connecting airtight member 100 are connected in a non-air permeable manner using airtight tape. The location where the airtight tape is attached has already been described.

[0055] In the support fixing step SA7, the joist support 8 is fixed to the indoor side of the cross member 50 at a position below the connecting airtight member 100, sandwiching the already installed lower floor airtight member 51 therebetween. Specifically, the pair of mounting plate portions 82 of the joist support 8 are abutted against the indoor side of the lower floor airtight member 51, and in this state the pair of mounting plate portions 82 are fixed to the cross member 50 together with the lower floor airtight member 51 with screws. In this way, the joist support 8 is fixed to the cross member 50, sandwiching the lower floor airtight member 51 therebetween.

[0056] In the joist installation step SA8, the longitudinal end of each joist 7 is engaged with the support body 81 (see FIG. 2 ) of the joist support 8, thereby connecting the joists 7 to the cross member 50 via the joist support 8. When installation of the joists 7 is complete, the lower floor airtight member 51 is sandwiched between the longitudinal end face of the joist 7 and the indoor side face of the cross member 50. Note that this sandwiched state is not shown in FIGS. 1 and 3 , but this is because the thicknesses of the lower floor airtight member 51 and the connecting airtight member 100 are exaggerated and depicted as thicker than they actually are; in reality, the lower floor airtight member 51 is sandwiched between the end face of the joist 7 and the cross member 50.

[0057] In the floor member installation step SA9, the edge of the underfloor material 22 is engaged with the covering portion 101 of the already installed connecting airtight member 100 from the indoor side, and the underside of the underfloor material 22 is supported on the upper surface of each joist 7. After the installation of the underfloor material 22 is completed, the floor finishing material 21 is fixed to the upper surface of the underfloor material 22 with an adhesive or the like. The floor finishing material 21 and the underfloor material 22 may be previously joined together to form a single floor panel unit.

[0058] Also, the floor finishing material 21, the floor underlayment 22, and the joists 7 may be previously joined together to form a single floor panel unit. In this case, a joist installation step SA8 in which the ends of the joists 7 constituting the floor panel are engaged with the joist supports 8 and a floor member installation step SA9 in which the edge of the floor finishing material 21 is engaged with the covering portion 101 of the connecting airtight member 100 are simultaneously performed.

[0059] [Effects] As described above, in this embodiment, the building 1 comprises an upper floor airtight member 41 arranged along the surface of the upper floor wall 4 at a position overlapping the floor underlayment 22 (an example of a floor member) in a plan view, a lower floor airtight member 51 arranged along the surface of the lower floor wall 5 at a position overlapping the floor underlayment 22 (an example of a floor member) in a plan view, and a connecting airtight member 100 formed continuously and seamlessly, extending from the upper side to the lower side of the edge of the floor underlayment 22 to connect the upper floor airtight member 41 and the lower floor airtight member 51 (see Figures 1 and 3).

[0060] According to this configuration, the airtight line formed by the upper floor airtight member 41 and the airtight line formed by the lower floor airtight member 51 can be continuously connected via the connecting airtight member 100. Therefore, the continuity of the airtight line extending from the upper floor wall portion 4 to the lower floor wall portion 5 can be prevented from being interrupted by the underfloor material 22. Furthermore, according to the above configuration, the connecting airtight member 100 itself is formed continuously and seamlessly, so the labor required for installing the connecting airtight member 100 can be significantly reduced compared to, for example, a case in which a connecting airtight member is formed by joining multiple members. Furthermore, in a building 1 in which the edge portions of the underfloor material 22 are supported on the top surfaces of the cross members 50 as in the above configuration, the underfloor material 22 functions like a brace in a steel-frame building, preventing lateral movement of the building 1 and increasing stability. On the other hand, because horizontal lateral loads act on the edges of the underfloor material 22, if a connecting member is formed by joining multiple members as described above, there is a risk that this lateral load will damage the connecting airtight member. In contrast, with the above-described configuration, by forming a single connecting airtight member 100 continuously and seamlessly, it is possible to prevent the connecting airtight member 100 from breaking due to such lateral loads. Therefore, while ensuring the function of the underfloor material 22 as a brace, it is possible to prevent damage to the connecting airtight member 100 due to the lateral load and ensure the continuity of the airtight line from the upper floor wall 4 to the lower floor wall 5.

[0061] In addition, in this embodiment, the connecting airtight member 100 has a covering portion 101 that extends from the upper surface of the edge portion of the floor underlayment 22, via the outer end surface of the floor underlayment 22, to the underside of the edge portion and also extends in the extension direction of the cross member 50, covering the edge portion, an upper connecting portion 102 that extends upward from the indoor end of the upper indoor side of the covering portion 101 and is connected to the upper floor airtight member 41, and a lower connecting portion 103 that extends downward from the indoor end of the lower indoor side of the covering portion 101 and is connected to the lower floor airtight member 51 (see Figures 1 and 3).

[0062] According to this configuration, the positioning of the linked airtight member 100 can be performed easily and accurately by engaging the covering portion 101 of the linked airtight member 100 with the edge portion of the underfloor material 22. This prevents the linked airtight member 100 from being misaligned when assembled, and in turn prevents poor connection between the linked airtight member 100 and the upper floor airtight member 41 and between the linked airtight member 100 and the lower floor airtight member 51. Furthermore, according to the above configuration, by engaging the covering portion 101 with the edge portion of the underfloor material 22, the linked airtight member 100 can be compactly arranged in a narrow space around the edge portion.

[0063] Furthermore, according to the construction method of the connecting airtight member 100 of this embodiment, in the first connecting step SA4 (see FIG. 5 ), the lower end of the upper floor airtight member 41 is connected to the upper connecting portion 102 of the connecting airtight member 100, and in the second connecting step SA6, the upper end of the lower floor airtight member 51 is connected to the lower connecting portion 103 of the connecting airtight member 100, thereby continuously connecting the airtight line formed by the upper floor airtight member 41 and the airtight line formed by the lower floor airtight member 51 via the connecting airtight member 100. Therefore, the continuity of the airtight line from the upper floor wall portion 4 to the lower floor wall portion 5 can be ensured. Furthermore, according to the construction method, in the support fixing step SA7, the joist support 8 is fixed to the indoor side of the cross member 50 with the lower floor airtight member 51 sandwiched therebetween, thereby eliminating the need to perform work such as cutting off the portion of the lower floor airtight member 51 corresponding to the joist support 8. Therefore, the installation work of the lower floor airtight member 51 can be easily carried out.

[0064] 6 and 7 are equivalent to FIGS. 1 and 3 and show a building 1 of a second embodiment. This second embodiment differs from the first embodiment in that the portion of the lower floor airtight member 51 corresponding to the joist support 8 is removed, and the joist support 8 is attached directly to the indoor side of the cross member 50 without overlapping with the lower floor airtight member 51. In the following embodiments, the same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

[0065] 6 and 7, a notch 51a is formed in the lower floor airtight member 51 in a portion corresponding to the joist support 8. The shape of the notch 51a corresponds to the shape of the joist support 8 projected onto the cross member 50 when viewed from the width direction of the building. It is preferable to apply airtight tape to the boundary between the outer edge of this notch 51a and the joist support 8 to make it airtight. This ensures airtightness at the boundary between the notch 51a and the joist support 8. The joist support 8 is fixed to the indoor side of the cross member 50 with mounting screws, with a pair of mounting plate portions 82 abutting against the indoor side of the cross member 50.

[0066] Fig. 8 is a flowchart showing an example of a method for installing the linked airtight member 100 in embodiment 2. The method for installing the linked airtight member 100 will be described below with reference to the flow chart of Fig. 8 and the vertical cross-sectional view of Fig. 6 as appropriate.

[0067] The construction method includes a preparation step SB0, a connecting airtight member assembly step SB1, a support fixing step SB2, a joist installation step SB3, a floor member installation step SB4, an indoor-side insulation layer arrangement step SB5, an upper floor airtightness step SB6, a first connection step SB7, a lower floor airtightness step SB8, and a second connection step SB9. In this example, these steps SB0 to SB9 are performed in this order, but the order of execution is not limited to this, and the order of execution may be changed as appropriate within the physically possible range.

[0068] The preparation step SB0 and the connected airtight member assembling step SB1 are the same as the preparation step SA0 and the connected airtight member assembling step SA1 of the first embodiment, and therefore a description thereof will be omitted.

[0069] In the support fixing step SB2, the joist supports 8 are fixed to the indoor side of the cross member 50. Specifically, the pair of mounting plate portions 82 of the joist supports 8 are brought into contact with the indoor side of the cross member 50, and in this state, the pair of mounting plate portions 82 are fixed directly to the cross member 50 with screws (without sandwiching the lower floor airtight member 51).

[0070] In the joist installation process SB3, the longitudinal ends of each joist 7 are engaged with the support body portion 81 (see Figure 2) of the joist support 8, thereby connecting the joists 7 to the cross member 50 via the joist support 8.

[0071] After the joist installation step SB3 is performed, the floor member installation step SB4, the indoor-side insulation layer arrangement step SB5, the upper floor airtightness step SB6, and the first connection step SB7 are sequentially performed. These steps SB4 to SB7 are similar to the floor member installation step SA9, the indoor-side insulation layer arrangement step SA2, the upper floor airtightness step SA3, and the first connection step SA4 in the first embodiment, and therefore detailed descriptions thereof will be omitted.

[0072] After the first connecting step SB7 is performed, the lower floor airtight step SB8 is performed. In the lower floor airtight step SB8, the lower floor airtight member 51 is positioned along the surface direction of the lower floor wall portion 5 (in other words, parallel to the wall surface of the lower floor wall portion 5). Specifically, the position of the lower floor airtight member 51 is adjusted so that the upper end of the lower floor airtight member 51 overlaps the lower connection portion 103 of the connecting airtight member 100 from the inside of the building (an example of the inside / outside direction of the building). Then, the lower floor airtight member 51 is fixed to the indoor side of the lower floor wall framework portion 5F using staples, tape, etc.

[0073] Here, the lower floor airtightness step SB8 of this embodiment includes a cutting step SB81 of forming the notch 51a in the lower floor airtight member 51 by cutting out a portion of the lower floor airtight member 51 that corresponds to the joist support 8. The lower floor airtightness step SB8 may further include a cut-out portion airtightness step SB82 of applying airtight tape to the boundary between the cut-out portion 51a of the lower floor airtight member 51 and the joist support 8. This ensures airtightness at the boundary (edge ​​of the cut-out portion) between the lower floor airtight member 51 and the joist support 8. The airtight tape may have an adhesive surface on only one side or on both sides.

[0074] After the lower floor airtightness step SB8 is performed, in the second connection step SB9, the upper end of the lower floor airtight member 51 and the lower connection part 103 of the connecting airtight member 100 are connected together using airtight tape so as to be airtight. The location where the airtight tape is applied has already been explained.

[0075] [Effects] As described above, according to the installation method of the connecting airtight member 100 of this embodiment, in the first connecting step SB7, the lower end of the upper floor airtight member 41 is connected to the upper connecting portion 102 of the connecting airtight member 100, and in the second connecting step SB9, the upper end of the lower floor airtight member 51 is connected to the lower connecting portion 103 of the connecting airtight member 100. This allows the airtight line formed by the upper floor airtight member 41 and the airtight line formed by the lower floor airtight member 51 to be continuously connected via the connecting airtight member 100. Therefore, the same effects as those of the first embodiment can be obtained. Moreover, according to the installation method, in the cutting step SB81 of the lower floor airtight step SB8, the portion of the lower floor airtight member 51 corresponding to the joist support 8 is cut off. Therefore, the joist support 8 can be directly abutted against the indoor side of the cross member 50 and fixed thereto without interposing the lower floor airtight member 51 between the joist support 8 and the cross member 50. Therefore, the joist support 8 can be firmly fixed to the cross member 50.

[0076] 9 and 10 are views equivalent to FIGS. 1 and 3 showing a building 1 of embodiment 3. In this embodiment 3, the lower floor airtight member 51 comprises a lower floor airtight main body 510 made of an airtight sheet or the like and a urethane foam layer 511 connected to the upper end thereof, and is different from embodiment 1 in that the lower connection portion 103 of the connecting airtight member 100 is connected to the urethane foam layer 511 (part of the lower floor airtight member 51).

[0077] 9 and 10, the lower floor airtight main body 510 is disposed so that its upper edge is positioned slightly below the joist support 8. Specifically, the upper edge of the lower floor airtight main body 510 extends linearly in the depth direction of the building along the indoor side surface of the cross member 50 at a position slightly below the joist support 8.

[0078] The urethane foam layer 511 is formed so as to straddle the indoor side surface of the upper end of the lower floor airtight main body 510 and the indoor side surface of the lower connection part 103 of the connecting airtight member 100. The urethane foam layer 511 is formed so as to cover the indoor side surface of the cross member 50, and constitutes part of the lower floor airtight member 51. The urethane foam layer 511 is formed by spraying urethane foam after the joist supports 8 are installed, as will be described later.

[0079] Fig. 11 is a flowchart showing an example of a method for installing the linked airtight member 100 in embodiment 3. The method for installing the linked airtight member 100 will be described below with reference to the flow chart of Fig. 11 and the vertical cross-sectional view of Fig. 9 as appropriate.

[0080] The construction method includes a preparation step SC0, a connecting airtight member assembly step SC1, a support fixing step SC2, a joist installation step SC3, a floor member installation step SC4, an indoor-side insulation layer arrangement step SC5, an upper floor airtightness step SC6, a first connection step SC7, a lower floor airtightness step SC8, and a second connection step SC9. In this example, these steps SC0 to SC9 are performed in this order, but the order of execution is not limited to this, and the order of execution may be changed as appropriate within the physically possible range.

[0081] The contents of each process SC0 to SC9 will be explained below, but since the processes from the connecting airtight member assembly process SC1 to the first connection process SC7 are the same as the processes from the connecting airtight member assembly process SC1 to the first connection process SC7 in embodiment 2, detailed explanations will be omitted and only the preparation process SC0, the lower floor airtight process SC8, and the second connection process SC9 will be explained.

[0082] The preparation step SC0 is a step of preparing the structure of the building 1, which includes the cross members 50, the upper floor wall portions 4, the lower floor wall portions 5, the upper floor airtight members 41, the lower floor airtight main bodies 510 of the lower floor airtight members 51, and the connecting airtight members 100. In other words, the preparation step SC0 is a step of completing the construction of these members in advance.

[0083] In the lower floor airtightness step SC8, the lower floor airtight main body 510 is positioned so as to be aligned along the surface of the lower floor wall 5 (in other words, parallel to the wall surface of the lower floor wall 5). At this time, the position of the lower floor airtight main body 510 is adjusted so that the upper edge of the lower floor airtight main body 510 is positioned slightly below the joist support 8. Then, the lower floor airtight main body 510 is fixed to the indoor side of the lower floor wall framework 5F using staples, tape, etc.

[0084] In the second connecting step SC9, the urethane foam layer 511 is formed by spraying urethane foam onto an area spanning the lower connecting portion 103 of the connecting airtight member 100 and the upper end of the lower floor airtight main body portion 510 when viewed from the indoor side of the cross member 50. This results in an impermeable connection between the lower connecting portion 103 of the connecting airtight member 100 and the urethane foam layer 511, which is the upper end of the lower floor airtight member 51, and further results in an impermeable connection between the lower connecting portion 103 and the lower floor airtight main body portion 510 via the urethane foam layer 511. Here, in order to improve the airtightness at the attachment points of the joist supports 8, an airtight sheet may be attached in advance to the indoor side of the cross member 50 at least in the area corresponding to the attachment points of the joist supports 8 before the joist supports 8 are attached, and the lower floor airtight main body 510 and the lower connection part 103 of the connecting airtight member 100 are connected via the airtight sheet, after which the urethane foam is sprayed on. The attachment area of ​​this airtight sheet may extend, for example, in the width direction of the cross member 50, or may be only in the area corresponding to the attachment points of the joist supports 8.

[0085] [Effects] As described above, according to the installation method of the connecting airtight member 100 of this embodiment, in the first connecting step SC7, the lower end of the upper floor airtight member 41 is connected to the upper connecting part 102 of the connecting airtight member 100, and in the second connecting step SC9, the upper end of the lower floor airtight member 51 (in this example, the urethane foam layer 511) is connected to the lower connecting part 103 of the connecting airtight member 100, thereby continuously connecting the airtight line formed by the upper floor airtight member 41 and the airtight line formed by the lower floor airtight member 51 via the connecting airtight member 100. Therefore, the same effects as in embodiment 1 can be obtained. Moreover, according to the construction method, in the second connection step SC9, the lower floor airtight main body 510 and the lower connection part 103 of the connecting airtight member 100 are connected by spraying urethane foam, so that the upper end of the lower floor airtight main body 510 and the lower connection part 103 of the connecting airtight member 100 can be easily connected by spraying urethane foam with the upper end position of the lower floor airtight main body 510 positioned below the joist support 8. Therefore, there is no need to perform a step of cutting out the part of the lower floor airtight main body 510 that corresponds to the joist support 8, which makes the work easier.

[0086] (Embodiment 4) Fig. 12 is a view equivalent to Fig. 4 showing embodiment 4. This embodiment 4 differs from embodiment 1 in that the building 1 includes a column airtight member 120 and a pair of beam airtight members 110 (only one of which is shown in Fig. 12) as connecting airtight members.

[0087] Specifically, the building 1 includes a main pillar 18 and a pair of cross members 50 (only one of which is shown in FIG. 12 ) that extend in opposite directions across the main pillar 18 and are connected to the main pillar 18. In FIG. 12 , the cross member 50 is arranged only on the right side of the main pillar 18, but in reality, a cross member 50 (not shown) is also arranged symmetrically on the left side, and the same airtight structure as the right side is applied to the cross member 50 on the left side.

[0088] Each cross member airtight member 110 has the function of ensuring the continuity of the airtight line between the upper floor airtight member 41 and the lower floor airtight member 51 in the portion where each cross member 50 is installed. The cross member airtight member 110 is configured in the same manner as the connecting airtight member 100 of embodiment 1. That is, the cross member airtight member 110 has a cross member covering portion 111, a cross member upper connecting portion 112, and a cross member lower connecting portion 113. The configurations of the cross member covering portion 111, the cross member upper connecting portion 112, and the cross member lower connecting portion 113 are the same as the configurations of the covering portion 101, the upper connecting portion 102, and the lower connecting portion 103 of embodiment 1, and therefore detailed description thereof will be omitted.

[0089] The column airtight member 120 has the function of ensuring the continuity of the airtight line between the upper floor airtight member 41 and the lower floor airtight member 51 in the area where the main column 18 is located.

[0090] 13 is a perspective view showing the column airtight member 120. As shown in this figure, the column airtight member 120 has a pair of side portions 121 that face each other across the main column 18 (an example of a column member) in the depth direction of the building (the extension direction of the cross member 50), and a connecting portion 122 that connects the pair of side portions 121.

[0091] Each of the pair of side portions 121 has a side covering portion 121a, an upper side connecting portion 121b, a lower side connecting portion 121c, and a closing portion 121d.

[0092] The side covering portion 121a is formed with a U-shaped cross section that opens toward the indoor side so as to engage with the edge portion of the underfloor material 22 (an example of a floor member).

[0093] The upper side connection portion 121b extends upward from the indoor-side upper edge of the side covering portion 121a and is connected to the upper floor airtight member 41. Specifically, the upper side connection portion 121b is arranged so as to overlap the upper floor airtight member 41 from the outside of the building (an example of the inside-outside direction of the building). The upper side connection portion 121b and the upper floor airtight member 41 are connected in a breathable manner using airtight tape or the like.

[0094] The lower side connection portion 121c extends downward from the lower edge of the indoor side of the side covering portion 121a and is connected to the lower floor airtight member 51. Specifically, the lower side connection portion 121c is arranged so as to overlap the lower floor airtight member 51 from the outside of the building (an example of the inside-outside direction of the building). The lower side connection portion 121c and the lower floor airtight member 51 are connected in a breathable manner using airtight tape or the like.

[0095] The closing portion 121d is formed in a plate shape that closes the opening in the side covering portion 121a that faces the main column 18. Double-sided tape 123 is attached to this closing portion 121d. When the column airtight member 120 is attached to the main column 18, the closing portion 121d is fixed to the side surface of the main column 18 via this double-sided tape 123.

[0096] The connecting portion 122 is in the form of a flat plate extending along the indoor side surface of the main pillar 18, and is formed so as to connect the inner edges of the pair of side portions 121. The connecting portion 122 is formed so as to be continuously connected to the side upper connection portion 121b and the side lower connection portion 121c, forming a single flat plate. The connecting portion 122 is formed from the upper side to the lower side of the underfloor material 22 when viewed from the indoor side. A pair of double-sided tapes 124 extending in the vertical direction is affixed to the contact surface of the connecting portion 122 with the main pillar 18. The connecting portion 122 is fixed to the indoor side surface of the main pillar 18 via the double-sided tapes 124.

[0097] As shown in Fig. 12 , the column airtight member 120 is arranged so that the main column 18 engages between a pair of side portions 121 and the connecting portion 122 abuts against the indoor side of the main column 18. The column airtight member 110 is arranged so that its longitudinal end overlaps one side portion 121 of the column airtight member 120 (the right side portion 121 in the example of Fig. 12 ) from the indoor side (an example of the direction from the inside to the outside of the building) (see the two-dot chain line in Fig. 12 ).

[0098] [Operation and Effect] As described above, in this embodiment, the building 1 includes a pair of cross members 50 extending in opposite directions to each other, and main columns 18 disposed between the pair of cross members 50 and connected to each of the cross members 50. The building 1 also includes, as connecting airtight members, column airtight members 120 attached to the connection portions of the main columns 18 with the cross members, and a pair of cross member airtight members 110 extending along the pair of cross members 50 and attached to each of the cross members 50. The column airtight members 120 and the pair of cross member airtight members 110 connect the upper floor airtight member 41 and the lower floor airtight member 51 (not shown in FIG. 12 ) in a state in which a portion of the column airtight member 120 and a portion of the pair of cross member airtight members 110 are overlapped with each other in the interior and exterior directions of the building.

[0099] According to this configuration, the column airtight member 120 and the pair of cross member airtight members 110 can form a continuous airtight line in the extension direction of the cross member 50. That is, in the portion where the main column 18 is located, the column airtight member 120 forms a continuous airtight line in the vertical direction extending from the upper floor airtight member 41 to the lower floor airtight member 51, and in the portion where the cross member 50 is located, the column airtight member 110 forms a continuous airtight line in the vertical direction extending from the upper floor airtight member 41 to the lower floor airtight member 51. These airtight lines are continuous in the extension direction of the cross member 50 without being interrupted at the boundary between the column airtight member 120 and the pair of cross member airtight members 110 because a portion of the column airtight member 120 (side portion 121 in this example) and a portion of the pair of cross member airtight members 110 (longitudinal ends in this example) overlap in the inside / outside direction of the building. Therefore, the airtightness of the building 1 can be improved as much as possible.

[0100] Specifically, in this embodiment, the column airtight member 120 has a pair of side portions 121 located on both sides of the main column 18 in the extension direction of the cross member 50, and a portion 122 extending along the indoor side of the main column 18 to connect the pair of side portions 121. The pair of side portions 121 each have a side covering portion 121a that extends from the upper surface of the edge portion of the floor underlayment 22 via the outer end surface of the floor underlayment 22 to the underside of the edge portion so as to cover the edge portion; an upper side connection portion 121b that extends upward from the upper edge of the indoor side of the side covering portion 121a and is connected to the upper floor airtight member 41; a lower side connection portion 121c that extends downward from the lower edge of the indoor side of the side covering portion 121a and is connected to the lower floor airtight member 51; and a blocking portion 121d that blocks the opening of the side covering portion 121a facing the main column 18, and the pair of side portions 121 are arranged so as to overlap the end of the airtight member 110 for the cross member in the interior and exterior directions of the building.

[0101] With this configuration, the column airtight member 120 can be attached to the main column 18 from the indoor side by engaging the main column 18 between the pair of side portions 121 and abutting the connecting portion 122 against the indoor side of the main column 18. Then, with the column airtight member 120 attached to the main column 18, by connecting the upper floor airtight member 41 to the portion of the connecting portion 122 above the underfloor material 22 and connecting the lower floor airtight member 51 to the portion of the connecting portion 122 below the underfloor material 22, it is possible to ensure the continuity of the airtight line extending from the upper floor wall portion 4 to the lower floor wall portion 5 even in the portion where the main column 18 is located. Furthermore, a pair of side portions 121 of the column airtight member 120 are arranged so as to overlap the ends of each cross member airtight member 110 in the inside-outside direction of the building, so that the column airtight member 120 and each cross member airtight member 110 can form a continuous airtight line in the extension direction of the cross member 50.

[0102] In addition, in this embodiment, each airtight member 110 for a cross member has a covering portion 111 for a cross member that extends from the upper surface of the edge portion of the floor underlayment material 22 via the outer end surface of the floor underlayment material 22 to the underside of the edge portion so as to cover the edge portion, an upper connecting portion 112 for a cross member that extends upward from the upper edge of the indoor side of the covering portion 111 for a cross member and is connected to the upper floor airtight member 41, and a lower connecting portion 113 for a cross member that extends downward from the lower edge of the indoor side of the covering portion 111 for a cross member and is connected to the lower floor airtight member 51.

[0103] According to this configuration, in the area where a pair of cross members are provided, the airtight members for each cross member can ensure the continuity of the airtight line extending from the airtight member for the upper floor to the airtight member for the lower floor.

[0104] The above-described specific embodiments mainly include inventions having the following configurations.

[0105] A building according to one aspect of the present invention comprises a lower floor and an upper floor adjacent to the upper side of the lower floor, and is equipped with: a cross member arranged between the upper and lower floors; a floor member of the upper floor having an edge portion supported on the upper surface of the cross member; an upper floor wall portion and a lower floor wall portion arranged on the upper floor side and the lower floor side, respectively, sandwiching the floor member and overlapping the edge portion of the floor member in a planar view; an upper floor airtight member arranged along the surface direction of the upper floor wall portion at a position overlapping the floor member in a planar view; a lower floor airtight member arranged along the surface direction of the lower floor wall portion at a position overlapping the floor member in a planar view; and a connecting airtight member formed continuously and seamlessly, extending at least from above to below the edge portion of the floor member, so as to connect the upper floor airtight member and the lower floor airtight member.

[0106] According to the above configuration, in a building in which the edge portions of floor members are supported on the upper surfaces of cross members, the continuity of the airtight line from the wall portion of the upper floor to the wall portion of the lower floor can be ensured. That is, in conventional buildings without connecting airtight members, the continuity between the airtight members of the upper floor and the airtight members of the lower floor is interrupted by the floor member being sandwiched between them. However, according to the above configuration, by disposing the connecting airtight members from the upper side to the lower side of the edge portions of the floor members and connecting the airtight members of the upper floor and the airtight members of the lower floor by the connecting airtight members, the airtight line formed by the airtight members of the upper floor and the airtight line formed by the airtight members of the lower floor can be continuously connected via the connecting airtight members. Therefore, the continuity between the airtight members of the upper floor and the airtight members of the lower floor can be prevented from being interrupted by the floor members. Furthermore, with the above configuration, the connected airtight member itself is formed continuously and seamlessly, significantly reducing the labor required for construction compared to, for example, a case in which a connected airtight member is constructed by joining multiple components. Furthermore, in a building in which the edges of floor members are supported on the top surfaces of cross members as in the above configuration, the floor members function like braces in a steel-frame building, preventing lateral movement of the building and increasing stability. On the other hand, because horizontal lateral loads act on the edges of the floor members, when multiple components are joined together to form a connected member as described above, this lateral load may damage the connected airtight member. In contrast, with the above configuration, by forming a single connected airtight member continuously and seamlessly, fracture of the connected airtight member due to the lateral load can be suppressed. Therefore, the function of the floor members as braces can be maintained while preventing damage to the connected airtight member and ensuring the continuity of the airtight line from the upper floor wall to the lower floor wall. The airtight line is defined as a surface that blocks air flow in the direction of the building (thickness direction of each wall section) when viewed from the extending direction of the cross member. Furthermore, "the connecting airtight member is formed continuously and seamlessly" means that one connecting airtight member is formed continuously and seamlessly in the vertical direction, and when multiple connecting airtight members are used, they may be connected to each other with seams in the extending direction of the cross member.

[0107] In the building, it is preferable that the connecting airtight member has a covering portion that extends from the upper surface of the edge portion of the floor member via the outer end surface of the floor member to the underside of the edge portion and also extends in the extension direction of the cross member, covering the edge portion, an upper connecting portion that extends upward from the indoor end of the upper part of the covering portion and is connected to the upper floor airtight member, and a lower connecting portion that extends downward from the indoor end of the lower part of the covering portion and is connected to the lower floor airtight member.

[0108] According to the above configuration, the positioning of the connecting airtight member can be easily and accurately performed by engaging the covering portion of the connecting airtight member with the edge portion of the floor member. This prevents the connecting airtight member from being misaligned when assembled, thereby preventing poor connections between the connecting airtight member and the airtight member of the upper floor and between the connecting airtight member and the airtight member of the lower floor. Furthermore, according to the above configuration, by engaging the covering portion with the edge portion of the floor member, the connecting airtight member can be compactly arranged in the narrow space around the edge portion, thereby improving space efficiency.

[0109] The building further comprises a pair of cross members extending in opposite directions to each other, and column members arranged between the pair of cross members and connected to each of the cross members, and the connecting airtight member includes a column airtight member attached to the connection portion of the column member with the cross member, and a pair of cross member airtight members extending along the pair of cross members and attached to each of the cross members, and it is preferable that the column airtight member and the pair of cross member airtight members connect the upper floor airtight member and the lower floor airtight member with a state in which a portion of the column airtight member and a portion of the pair of cross member airtight members are overlapped with each other in the interior and exterior directions of the building.

[0110] According to the above configuration, the column airtight member and the cross member airtight member can form a continuous airtight line in the extension direction of the cross member. That is, in the area where the column member is located, the column airtight member forms a continuous airtight line in the vertical direction extending from the airtight member for the upper floor to the airtight member for the lower floor, and in the area where the cross member is located, the cross member airtight member forms a continuous airtight line in the vertical direction extending from the airtight member for the upper floor to the airtight member for the lower floor. These airtight lines are continuous in the extension direction of the cross member without being interrupted at the boundary between the column airtight member and the pair of cross member airtight members, because a portion of the column airtight member and a portion of the pair of cross member airtight members overlap in the interior / exterior direction of the building. This allows the airtightness of the building to be improved as much as possible.

[0111] In the building, the column airtight member has a pair of side portions located on either side of the column member in the extension direction of the cross member, and a connecting portion extending along the indoor side of the column member to connect the pair of side portions, and the pair of side portions each have a side covering portion extending from the upper surface of the edge portion via the outer end surface of the floor member to the underside of the edge portion so as to cover the edge portion of the floor member, an upper side connecting portion extending upward from the indoor upper edge of the side covering portion and connected to the upper floor airtight member, a lower side connecting portion extending downward from the indoor lower edge of the side covering portion and connected to the lower floor airtight member, and a closing portion that closes the opening of the side covering portion facing the column member, and it is preferable that the pair of side portions are arranged so as to overlap the end of the cross member airtight member in the interior and exterior directions of the building.

[0112] According to the above configuration, the column airtight member can be attached to the column member from the indoor side by engaging the column member between the pair of side portions and abutting the connecting portion against the indoor side of the column member. Then, with the column airtight member attached to the column member, an upper floor airtight member can be connected to the connecting portion above the floor member and a lower floor airtight member can be connected to the connecting portion below the floor member, thereby ensuring the continuity of the airtight line extending from the upper floor wall to the lower floor wall, even in the area where the column member is located. Furthermore, since the pair of side portions of the column airtight member are arranged so as to overlap the ends of the airtight members for each cross member in the interior / exterior direction of the building, the column airtight member and each cross member airtight member can form a continuous airtight line in the extension direction of the cross members.

[0113] In the building, it is preferable that each airtight member for a cross member has a covering portion for a cross member that extends from the upper surface of the edge portion via the outer end surface of the floor member to the underside of the edge portion so as to cover the edge portion of the floor member, an upper connecting portion for a cross member that extends upward from the upper edge of the indoor side of the covering portion for a cross member and is connected to the upper floor airtight member, and a lower connecting portion for a cross member that extends downward from the lower edge of the indoor side of the covering portion for a cross member and is connected to the lower floor airtight member.

[0114] According to the above configuration, in the area where a pair of cross members are provided, the continuity of the airtight line extending from the airtight member for the upper floor to the airtight member for the lower floor can be ensured by the airtight members for each cross member.

[0115] A method for installing connecting airtight members in a building according to another aspect of the present invention preferably includes the following steps: a preparation step for preparing the building configuration having the cross member, the upper floor wall portion, the lower floor wall portion, the upper floor airtight member, the lower floor airtight member, and the connecting airtight member; a support fixing step for fixing joist supports that support the longitudinal ends of the joists that support the floor members to the indoor side of the cross member, sandwiching the lower floor airtight members; a joist installation step for supporting the longitudinal ends of the joists with the joist supports; and a floor member installation step for installing the floor members on the joists and the cross member so that the edge portions of the floor members are covered by the covering portions.

[0116] According to the method, in the support fixing step, the joist supports that support the joists are fixed to the indoor side of the cross member with the lower floor airtight member sandwiched between them, which eliminates the need for work such as cutting off the portion of the lower floor airtight member that corresponds to the joist support, thereby making the work easier.

[0117] A method for installing connecting airtight members in a building according to another aspect of the present invention preferably includes the following steps: a preparation step for preparing the structure of the building having the cross member, the upper floor wall portion, the lower floor wall portion, the upper floor airtight member, the lower floor airtight member, and the connecting airtight member; a support fixing step for fixing joist supports for supporting the ends of the joists that support the floor members to a portion of the indoor side of the cross member that is lower than the connecting airtight members; a cutting step for cutting out portions of the lower floor airtight members that correspond to the joist supports prior to the support fixing step; a joist installation step for supporting the longitudinal ends of the joists on the joist supports; and a floor member installation step for installing the floor members on the joists and the cross member so that the edge portions of the floor members are covered by the covering portions.

[0118] According to the method, in the cutting step, the portion of the lower floor airtight member corresponding to the joist support is cut off, so that in the joist installation step, the joist support can be fixed by abutting it against the indoor side of the cross member without interposing a lower floor airtight layer between the joist support and the cross member. Thus, the joist support can be firmly fixed to the cross member.

[0119] A method for installing a connecting airtight member in a building according to another aspect of the present invention, wherein the lower floor airtight member has a lower floor airtight main body made of an airtight sheet and a urethane foam layer connected to an upper end of the lower floor airtight main body, and the method includes a preparation step of preparing a structure of the building having the cross member, the upper floor wall portion, the lower floor wall portion, the upper floor airtight member, the lower floor airtight main body portion of the lower floor airtight member, and the connecting airtight member; a support fixing step of fixing joist supports for supporting ends of joists that support the floor members to parts of the indoor side of the cross member that are below the connecting airtight member; and a step of fixing the longitudinal ends of the joists to the joist supports. a lower floor airtightness step of fixing the lower floor airtight main body portion to the lower floor wall portion so that the upper end position of the lower floor airtight main body portion of the lower floor airtight member is located lower than the joist support; a first connection step of connecting the lower end of the upper floor airtight member to the upper connection portion of the connecting airtight member; a second connection step of forming the urethane foam layer by spraying urethane foam so that the upper end of the lower floor airtight main body portion and the lower connection portion of the connecting airtight member are connected; and a floor member installation step of installing the floor members on the joists and cross members so that the edge portions of the floor members are covered by the covering portions.

[0120] According to the method, the upper end of the lower floor airtight main body and the lower connection part of the connecting airtight member are connected via a urethane foam layer (part of the lower floor airtight member) formed by spraying urethane foam, so that the upper end of the lower floor airtight main body and the lower connection part of the connecting airtight member can be easily connected via the urethane foam layer while the upper end of the lower floor airtight main body is positioned below the joist support. Therefore, there is no need for a process such as cutting out the part of the lower floor airtight main body that corresponds to the joist support, which makes the work easier.

[0121] (Other embodiments) The above describes the building 1 and the method for installing the connecting airtight member 100 according to an embodiment of the present invention, but the present invention is not limited to this, and for example, the following modified embodiments can be adopted.

[0122] (1) In the above-described embodiments, the connecting airtight member 100 extends from above to below the edge of the underfloor material 22, but the connecting airtight member 100 is not necessarily limited to a configuration that covers only the edge, and may be formed to cover the edge of the underfloor material 22 to the indoor side. In other words, it is sufficient that the connecting airtight member 100 is configured to extend from above to below at least the edge of the underfloor material 22.

[0123] (2) In the first to third embodiments, the workers in the steps of the method for installing the linked airtight member 100 are not limited to humans, but may be, for example, working robots.

[0124] (3) In addition, in the fourth embodiment, an example in which the column airtight member 120 is applied to the main column 18 has been described, but the present invention is not limited to this, and the column airtight member 120 may be applied to, for example, a partition or half column extending in the vertical direction across the cross member 50. In other words, the column airtight member 120 can be applied to any column member extending in the vertical direction and intersecting the cross member 50.

[0125] (4) The present invention also includes any combination of the above embodiments.

Claims

1. A building comprising a lower floor and an upper floor adjacent to the upper side of the lower floor, comprising: a cross member arranged between the upper and lower floors; a floor member of the upper floor having an edge portion supported on the upper surface of the cross member; an upper floor wall portion and a lower floor wall portion arranged on the upper floor side and the lower floor side, respectively, with the floor member in between, and overlapping the edge portion of the floor member in a plan view; an upper floor airtight member arranged along the surface direction of the upper floor wall portion at a position overlapping the floor member in a plan view; a lower floor airtight member arranged along the surface direction of the lower floor wall portion at a position overlapping the floor member in a plan view; and a connecting airtight member formed continuously and seamlessly, extending at least from the upper side to the lower side of the edge portion of the floor member, and connecting the upper floor airtight member and the lower floor airtight member.

2. A building as described in claim 1, wherein the connecting airtight member has a covering portion that extends from the upper surface of the edge portion of the floor member via the outer end surface of the floor member to the underside of the edge portion and also extends in the extension direction of the cross member, covering the edge portion; an upper connecting portion that extends upward from the indoor end of the upper part of the covering portion and is connected to the upper floor airtight member; and a lower connecting portion that extends downward from the indoor end of the lower part of the covering portion and is connected to the lower floor airtight member.

3. A building as claimed in claim 1 or 2, further comprising a pair of cross members extending in opposite directions to each other and column members arranged between the pair of cross members and connected to each of the cross members, wherein the connecting airtight member comprises a column airtight member attached to the connection portion of the column member with the cross member, and a pair of cross member airtight members extending along the pair of cross members and attached to each of the cross members, wherein the column airtight member and the pair of cross member airtight members connect the upper floor airtight member and the lower floor airtight member with a state in which a portion of the column airtight member and a portion of the pair of cross member airtight members are overlapped with each other in the interior and exterior directions of the building.

4. A building as described in claim 3, wherein the column airtight member has a pair of side portions provided on either side of the column member in the extension direction of the cross member, and a connecting portion extending along the indoor side surface of the column member to connect the pair of side portions, and the pair of side portions each have a side covering portion extending from the upper surface of the edge portion via the outer end surface of the floor member to the underside of the edge portion so as to cover the edge portion of the floor member, an upper side connecting portion extending upward from the indoor upper edge of the side covering portion and connected to the upper floor airtight member, a lower side connecting portion extending downward from the indoor lower edge of the side covering portion and connected to the lower floor airtight member, and a closing portion that closes the opening of the side covering portion facing the column member, and the pair of side portions are positioned so as to overlap the end of the cross member airtight member in the interior and exterior directions of the building.

5. In a building as claimed in claim 3 or 4, each airtight member for a cross member has a covering portion for a cross member that extends from the upper surface of the edge portion of the floor member via the outer end surface of the floor member to the underside of the edge portion so as to cover the edge portion, an upper connecting portion for a cross member that extends upward from the upper edge of the indoor side of the covering portion for a cross member and is connected to the airtight member for the upper floor, and a lower connecting portion for a cross member that extends downward from the lower edge of the indoor side of the covering portion for a cross member and is connected to the airtight member for the lower floor.

6. A method for installing the connecting airtight member in a building as described in claim 2, comprising: a preparation step for preparing the building configuration having the cross member, the upper floor wall portion, the lower floor wall portion, the upper floor airtight member, the lower floor airtight member, and the connecting airtight member; a support fixing step for fixing joist supports that support the longitudinal ends of the joists that support the floor members to the indoor side of the cross member, sandwiching the lower floor airtight member; a joist installation step for supporting the longitudinal ends of the joists on the joist supports; and a floor member installation step for installing the floor members on the joists and cross member so that the edge portions of the floor members are covered by the covering portion.

7. A method for installing the connecting airtight member in a building as described in claim 2, comprising: a preparation step for preparing the building configuration having the cross member, the upper floor wall portion, the lower floor wall portion, the upper floor airtight member, the lower floor airtight member, and the connecting airtight member; a support fixing step for fixing joist supports for supporting the ends of the joists that support the floor members to parts of the interior side of the cross member that are below the connecting airtight member; a cutting step for cutting out parts of the lower floor airtight member that correspond to the joist supports prior to the support fixing step; a joist installation step for supporting the longitudinal ends of the joists on the joist supports; and a floor member installation step for installing the floor members on the joists and the cross member so that the edge portions of the floor members are covered by the covering parts.

8. A method for installing the linked airtight member in a building as set forth in claim 2, wherein the lower floor airtight member has a lower floor airtight main body made of an airtight sheet and a urethane foam layer connected to the upper end of the lower floor airtight main body, and the method comprises: a preparation step for preparing the building configuration having the cross member, the upper floor wall portion, the lower floor wall portion, the upper floor airtight member, the lower floor airtight main body of the lower floor airtight member, and the linked airtight member; a support fixing step for fixing joist supports for supporting the ends of the joists that support the floor members to parts of the interior side of the cross member that are lower than the linked airtight member; a joist installation step for supporting the longitudinal ends of the joists on the joist supports; and a lower floor airtight step for fixing the lower floor airtight main body to the lower floor wall portion so that the upper end position of the lower floor airtight main body of the lower floor airtight member is located lower than the joist supports. A method for installing a connecting airtight member, comprising: a first connecting step for connecting the lower end of the upper floor airtight member and the upper connecting portion of the connecting airtight member; a second connecting step for forming a foamed urethane layer by spraying foamed urethane so that the upper end of the lower floor airtight main body and the lower connecting portion of the connecting airtight member are connected; and a floor member installing step for installing the floor member on the joists and cross members so that the edge portions of the floor member are covered by the covering portion.

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