Ceiling insulation construction method

Abstract

This ceiling insulation construction method comprises: a preparation step for preparing a first insulator (5A) and a second insulator (5B) each including an insulation material (51) and an airtight film (52) having a covering section (52a) that covers the entirety of a lower surface (51f) of the insulation material (51) and having a first surplus section (52b1) that extends outward from the lower surface (51f); a support member installation step for installing a support member (3); a first support step for causing the first insulator (5A) to be supported by the support member (3); a second support step for causing the second insulator (5B) to be supported by the support member (3) in a state in which the first surplus section (52b1) of the second insulator (5B) overlaps, from below, the covering section (52a) of the first insulator (5A); and a fusing step for fusing the first surplus section (52b1) to the covering section (52a) of the first insulator (5A) by applying heat to the first surplus section (52b1) and melting the same.

Description

Ceiling heat insulation construction method 【0001】 The present invention relates to a ceiling heat insulation construction method for insulating the ceiling part of a building. 【0002】 As one method for insulating the ceiling part of a building, for example, Patent Document 1 below discloses a method of attaching a heat insulating material to the frame space of a ceiling formed by a field edge and a base material. Specifically, in Patent Document 1, the heat insulating material has a mat and a moisture-proof film covering the lower surface of the mat. Further, the moisture-proof film has attachment support pieces protruding outward from the four side surfaces of the mat. When attaching the heat insulating material to the frame space, the mat is inserted into the frame space of the ceiling, and the above attachment support pieces protruding from the mat are fixed to the field edge and the base material using a gun tacker. 【0003】 In the above Patent Document 1, since the moisture-proof film covering the lower surface of the mat is fixed to the field edge and the base material, it is considered that the airtightness of the ceiling heat insulation part is improved. However, in the above Patent Document 1, in order to fix the attachment support pieces of the moisture-proof film to the field edge and the base material, it is necessary to repeatedly staple at regular intervals using a gun tacker, and there is room for improvement in terms of work efficiency. 【0004】 Japanese Patent Application Laid-Open No. 2002-146937 【0005】 The present invention has been made in view of the above circumstances, and an object thereof is to provide a ceiling heat insulation construction method capable of improving the efficiency of operations for enhancing the airtightness and heat insulation of the ceiling part of a building. 【0006】To solve the above problems, a method according to one aspect of the present invention is a ceiling insulation construction method for insulating the ceiling of a building, comprising: a preparation step of preparing a first insulating airtight member and a second insulating airtight member, each comprising an insulating material having a lower surface positioned facing the interior of the room, and an airtight film attached to the insulating material having a covering portion that covers the entire lower surface and an excess portion that extends to the outside of the lower surface; a support member installation step of installing support members for supporting the first insulating airtight member and the second insulating airtight member at predetermined installation locations; a first support step of supporting the first insulating airtight member on the support members; a second support step of supporting the second insulating airtight member on the support members with the excess portion of the second insulating airtight member overlapping the covering portion of the first insulating airtight member from below; and a welding step of melting the excess portion of the second insulating airtight member by applying heat of a predetermined temperature or higher to the excess portion of the second insulating airtight member and welding it to the covering portion of the first insulating airtight member. 【0007】 This is a bottom view of the ceiling of a building to which the ceiling insulation construction method according to the first embodiment of the present invention is applied, viewed from below. This is a cross-sectional view along line II-II in Figure 1. This is a partially broken longitudinal cross-sectional view along line III-III in Figure 1. This is a perspective view of the insulator viewed from diagonally below. This is a perspective view of the insulator viewed from diagonally above. This is a cross-sectional view along line VI-VI in Figure 1. This is a longitudinal cross-sectional view along line VII-VII in Figure 1. This is an enlarged cross-sectional view of a part of Figure 2. This is a perspective view showing the support member alone. This is a diagram showing the suspension member attached to a beam. This is a bottom view showing an enlarged view of the installation location of the suspension member. This is a diagram showing the support member and suspension member attached to the beam. This is a diagram showing the situation in which the first insulator is supported by the support member. This is a diagram showing the situation in which the second insulator is supported by the support member. This is a diagram showing the situation in which the excess portion of the second insulator is heated. This is a diagram showing the situation in which an additional airtight film is attached. This is a diagram corresponding to Figure 2 for explaining the second embodiment of the present invention. This is a perspective view of a part of the upper insulator viewed from diagonally below. 【0008】The embodiments of the present invention will be described below with reference to the attached drawings. Note that the following embodiments are examples that embody the present invention and are not intended to limit the technical scope of the present invention. 【0009】 (1) First Embodiment [Building Structure] Figure 1 is a bottom view of the ceiling of a building to which the ceiling insulation construction method according to the first embodiment of the present invention is applied, Figure 2 is a cross-sectional view along the line II-II in Figure 1, and Figure 3 is a partially broken longitudinal cross-sectional view along the line III-III in Figure 1. In the first embodiment, the directions front, back, left, right, up, and down are defined as shown in the figures, but this is just an example and is not intended to limit the installation orientation of each member. As shown in Figures 1 to 3, the building in the first embodiment comprises a floor base material 1 for the upper floor, a plurality of beams 2 arranged along the lower surface of the floor base material 1, a plurality of support members 3 and a plurality of suspension members 4 attached to the lower surface of the beams 2, a plurality of insulators 5 supported below the beams 2 by the support members 3, and a ceiling body 6 supported below the insulators 5 by the suspension members 4. Note that some of the insulators 5 are omitted in Figure 1. 【0010】 The subfloor material 1 is a structural element that constitutes the floor of the upper floor (e.g., the second floor) and is supported from below by beams 2. The subfloor material 1 includes a floor surface material placed on top of beams 2. The floor surface material is made of lightweight cellular concrete such as ALC. 【0011】 The beam 2 is a structural member that extends in the front-to-back direction (horizontal direction) along the underside of the floor base material 1. The beams 2 are arranged at approximately equal intervals in the left-to-right direction perpendicular to the front-to-back direction. In the first embodiment, the beam 2 is made of an H-shaped steel having a pair of flanges 21 arranged opposite each other in the vertical direction, and a web 22 connecting the central parts of both flanges 21. The upper flange 21 is fixed to the underside of the floor base material 1 using bolts or the like. 【0012】The ceiling structure 6 is a structural element that constitutes the ceiling of the lower floor (for example, the first floor), and is positioned below the floor base material 1 at a predetermined distance. A ceiling space S is formed between the floor base material 1 and the ceiling structure 6. Details are omitted, but the ceiling structure 6 includes, for example, a ceiling base including a joist support and joists fixed to the lower end of the suspension member 4, and a ceiling panel fixed to the lower surface of the ceiling base. In other words, the ceiling structure 6 is positioned below the floor base material 1 while being suspended by the suspension member 4. The ceiling structure 6 is an example of a "ceiling surface material" in the present invention. 【0013】 Multiple insulators 5 are components that enhance airtightness and heat insulation between the floor base material 1 and the ceiling structure 6, and are laid out in the space above the ceiling S. Specifically, the multiple insulators 5 are arranged below the beams 2 in the space above the ceiling S so as to be lined up without gaps in the front-to-back and left-to-right directions. 【0014】 As shown in Figure 1, one representative of the multiple insulators 5 is designated as the first insulator 5A. The insulator 5 to the left of the first insulator 5A is designated as the second insulator 5B, and the insulator 5 behind the first insulator 5A is designated as the third insulator 5C. In other words, the multiple insulators 5 include the first insulator 5A, the second insulator 5B which is positioned adjacent to the left of the first insulator 5A, and the third insulator 5C which is positioned adjacent to the rear of the first insulator 5A. The structures of these first to third insulators 5A to 5C and the other insulators 5 are basically the same. The first insulator 5A corresponds to an example of the "first heat-insulating and airtight member" in the present invention, and the second insulator 5B corresponds to an example of the "second heat-insulating and airtight member" in the present invention. Hereafter, when the first to third insulators 5A to 5C are not specifically distinguished, they will simply be referred to as insulator 5. 【0015】Figures 4 and 5 are perspective views showing the insulator 5 as a single unit. Figure 4 shows the insulator 5 viewed from diagonally below, and Figure 5 shows the insulator 5 viewed from diagonally above. As shown in Figures 4 and 5, the insulator 5 includes a rectangular parallelepiped-shaped thermal insulation material 51 and an airtight film 52 attached to the thermal insulation material 51. 【0016】 The thermal insulation material 51 can be of any type as long as it has thermal insulation properties, but in the first embodiment, a rigid thermal insulation material such as foamed urethane is used as the thermal insulation material 51. The thermal insulation material 51 has four circumferential surfaces: a right surface 51a and a left surface 51b that face each other in the left-right direction, and a front surface 51c and a rear surface 51d that face each other in the front-rear direction. The thermal insulation material 51 also has a bottom surface 51f that faces the interior of the room and an upper surface 51e on the opposite side. 【0017】 The airtight film 52 is a flexible film made of a thermoplastic resin such as polyethylene, polypropylene, or polyvinyl chloride. The airtight film 52 is attached so as to cover the lower surface 51f of the insulation material 51. Specifically, the airtight film 52 is formed in a rectangular shape having a larger area than the lower surface 51f of the insulation material 51, and is fixed to the lower surface 51f of the insulation material 51 by adhesive so as to cover the entire lower surface 51f of the insulation material 51. In this adhesive state, a part of the airtight film 52 extends to the outside of the lower surface 51f of the insulation material 51. That is, the airtight film 52 integrally has a rectangular covering portion 52a in plan view that covers the entire lower surface 51f of the insulation material 51, and an L-shaped excess portion 52b in plan view that extends from two orthogonal sides of the covering portion 52a to the outside of the lower surface 51f of the insulation material 51. Specifically, the excess portion 52b has a first excess portion 52b1 that extends to the right (outward) beyond the right surface 51a of the insulation material 51, and a second excess portion 52b2 that extends forward (outward) beyond the front surface 51c of the insulation material 51. In Figures 4 and 5, the excess portion 52b is shown in color. The same applies to Figure 1. 【0018】The covering portion 52a has a first overlapping portion 52a1 at its left end, that is, the end opposite to the first excess portion 52b1 in the left-right direction. As will be described in detail later, this first overlapping portion 52a1 is the region where the first excess portion 52b1 of another insulator 5 adjacent in the left-right direction overlaps. 【0019】 Furthermore, the covering portion 52a has a second overlapping portion 52a2 at its rear end, that is, the end opposite to the second excess portion 52b2 in the front-rear direction. As will be described in detail later, this second overlapping portion 52a2 is the region where the second excess portion 52b2 of another insulator 5 adjacent in the front-rear direction overlaps. 【0020】 A first non-adhesive portion Q1 is formed on the first overlapping portion 52a1 of the covering portion 52a. A second non-adhesive portion Q2 is formed on the side edge of the covering portion 52a opposite to the first non-adhesive portion Q1, i.e., at the right end of the covering portion 52a. At these first and second non-adhesive portions Q1 and Q2, the airtight film 52 is not adhered to the lower surface 51f of the insulation material 51, and the two can be separated. Conversely, in the areas excluding the first and second non-adhesive portions Q1 and Q2, the airtight film 52 is adhered to the lower surface 51f of the insulation material 51. In other words, the airtight film 52 is adhered to the lower surface 51f of the insulation material 51 only at the first and second non-adhesive portions Q1 and Q2 in such a way that it can be separated from the lower surface 51f of the insulation material 51. These first and second non-adhesive portions Q1 and Q2 function as receiving openings for the first support portion 33 and the second support portion 34 of the support member 3, which will be described later, when the insulator 5 is attached to the ceiling space S. The first and second non-adhesive portions Q1 and Q2 are formed approximately in the center in the front-to-back direction at the left and right ends of the covering portion 52a. 【0021】Figure 6 is a cross-sectional view along the line VI-VI in Figure 1, showing the first insulator 5A and the second insulator 5B installed in the ceiling space S. As shown in this figure, the first insulator 5A and the second insulator 5B are positioned adjacent to each other in the left-right direction, that is, the left surface 51b of the insulation material 51 of the first insulator 5A and the right surface 51a of the insulation material 51 of the second insulator 5B face each other with almost no gap. In this state, the first excess portion 52b1 of the airtight film 52 of the second insulator 5B extends across the first boundary B1, which is the boundary between the two surfaces 51a and 51b, to the first insulator 5A side (to the right). The first excess portion 52b1 that has crossed the first boundary B1 covers the left end of the airtight film 52 of the first insulator 5A, that is, the first overlapping portion 52a1, from below. The first excess portion 52b1 and the first superimposed portion 52a1 are welded to each other in this overlapping state. As a result, the airtight film 52 of the first insulator 5A and the airtight film 52 of the second insulator 5B are integrally joined, and a continuous airtight line is formed between the first insulator 5A and the second insulator 5B. 【0022】Figure 7 is a vertical cross-sectional view along the line VII-VII in Figure 1, showing the first insulator 5A and the third insulator 5C installed in the ceiling space S. As shown in this figure, the first insulator 5A and the third insulator 5C are positioned adjacent to each other in the front-to-back direction, that is, the rear surface 51d of the insulation material 51 of the first insulator 5A and the front surface 51c of the insulation material 51 of the third insulator 5C face each other with virtually no gap. In this state, the second excess portion 52b2 of the airtight film 52 of the third insulator 5C extends across the second boundary B2, which is the boundary between the two surfaces 51c and 51d, to the first insulator 5A side (front). The second excess portion 52b2 beyond the second boundary B2 covers the rear end of the airtight film 52 of the first insulator 5A, that is, the second overlapping portion 52a2, from below. The second excess portion 52b2 and the second overlapping portion 52a2 are welded to each other in this overlapping state. As a result, the airtight film 52 of the first insulator 5A and the airtight film 52 of the third insulator 5C are integrally joined, and a continuous airtight line is formed between the first insulator 5A and the third insulator 5C. 【0023】 Figure 8 is an enlarged cross-sectional view of a part of Figure 2, and Figure 9 is a perspective view showing the support member 3 alone. As shown in this figure, the support member 3 is a member for supporting the insulator 5 below the beam 2 and is attached to the lower flange 21 of the beam 2. Specifically, the support member 3 includes a mounting portion 31 attached to the lower flange 21, an extension portion 32 extending downward from the mounting portion 31, a first support portion 33 extending to the right from the lower end of the extension portion 32, and a second support portion 34 extending to the left from the lower end of the extension portion 32. In the first embodiment, the support member 3 is a sheet metal product made by processing a single metal plate and integrally includes each of the above-described elements 31 to 34. 【0024】The mounting portion 31 is formed in a U-shape when viewed in the front-to-back direction, surrounding the left half of the flange 21. Specifically, the mounting portion 31 has an upper edge portion 31a positioned along the upper surface of the flange 21, a lower edge portion 31b positioned along the lower surface of the flange 21, and a connecting portion 31c that connects the left ends of the upper edge portion 31a and the lower edge portion 31b. The mounting portion 31 is locked to the flange 21 by sandwiching the flange 21 between the upper edge portion 31a and the lower edge portion 31b. 【0025】 A first leaf spring portion SP1 is formed on the upper edge portion 31a, which is partially cut downwards and bent upwards. The first leaf spring portion SP1 applies a downward biasing force to the upper surface of the flange 21. As a result, the mounting portion 31 is stably held on the flange 21. 【0026】 A second leaf spring portion SP2 is formed on the lower edge portion 31b, which is partially cut and bent downwards. The second leaf spring portion SP2 applies a downward biasing force to the upper surface 51e of the insulator 5. As a result, the insulator 5 is stably held between the lower edge portion 31b and the second support portion 34. 【0027】 The extension portion 32 is formed as a flat plate extending downward from the right end of the lower edge portion 31b. The extension portion 32 is positioned in the center of the flange 21 in the left-right direction, in other words, at a position corresponding to the web 22. 【0028】 The first support portion 33 is continuous with the rear half of the lower end of the extension portion 32 and is formed to extend to the right from the extension portion 32. The left end of the insulator 5 is placed on the first support portion 33. 【0029】 The second support portion 34 is continuous with the front half of the lower end of the extension portion 32 and is formed to extend to the left from the extension portion 32. The right end of the insulator 5 is placed on the second support portion 34. 【0030】As described above, the support member 3 supports the insulator 5 below the beam 2 with its mounting portion 31 attached to the flange 21 of the beam 2. That is, as shown in Figure 2, the pair of support members 3 attached to the beams 2 which are aligned in the left-right direction support the insulator 5 below the beam 2 by having the first support portion 33 of one of the support members 3 receive the left end of the insulator 5, and the second support portion 34 of the other support member 3 receive the right end of the insulator 5. 【0031】 As shown in Figures 1 and 3, the support members 3 are arranged at approximately equal intervals along the beam 2, corresponding to the dimensions of each insulator 5 arranged in the front-to-back direction. Each support member 3 is located near the center in the front-to-back direction at the side end of the corresponding insulator 5. 【0032】 Figure 10 shows the suspension member 4 attached to the beam 2. As shown in this figure, the suspension member 4 includes a mounting portion 41 attached to the lower flange 21 of the beam 2 via bolts 45, surrounding the left half of the flange 21; a nut 42 fixed to the right end of the mounting portion 41 located below the center of the flange 21; and a threaded rod 43 screwed into the nut 42, extending downward from the nut 42. The lower end of the threaded rod 43 is fixed to the base material (ceiling base) of the ceiling body 6, which extends horizontally. 【0033】 As shown in Figures 1 and 3, the suspension member 4 is arranged along the beam 2 in an alternating relationship with the support member 3. The suspension member 4 is positioned between adjacent insulators 5. Specifically, the suspension member 4 is positioned at a location corresponding to the intersection of four adjacent insulators 5 in the front-rear and left-right directions, more precisely, at a location corresponding to the intersection where the corners of each insulation material 51 in these four insulators 5 meet. In this state, the rod screw 43 of the suspension member 4 is sandwiched between adjacent insulation materials 51, except for its lower part. In other words, adjacent insulators 5 are supported by the support member 3 in such a way that a portion of the rod screw 43 is sandwiched between their insulation materials 51. 【0034】The threaded rod 43 of the suspension member 4 extends vertically, passing through the airtight film 52 of the insulator 5. The airtight film 52 has a hole formed therein to allow the threaded rod 43 to pass through. As shown in Figure 11, an additional airtight film 55 is attached to the point where the threaded rod 43 passes through the airtight film 52, in order to close the hole in the airtight film 52 for the threaded rod 43. The additional airtight film 55 is, for example, an adhesive and flexible film, and is attached to the lower surface of the airtight film 52, with the threaded rod 43 passing through the additional airtight film 55. The additional airtight film 55 seals the area around the threaded rod 43 airtightly by adhering closely to the circumferential surface of the threaded rod 43 through which it passes. The additional airtight film 55 is an example of "another airtight film" in the present invention. 【0035】 [Construction Method] Next, a specific example of an insulation construction method for installing insulators 5 in the ceiling (ceiling space S) of a building with the structure described above will be explained. It should be assumed that the floor subfloor 1 and the beams 2 beneath it have already been constructed as a prerequisite for performing the insulation construction. 【0036】 For insulation work, first, an insulator 5 having an insulating material 51 and an airtight film 52, as shown in Figures 4 and 5, is prepared. The number of insulators 5 to be prepared can be appropriately set according to the size of the building's ceiling, etc. 【0037】 Next, as shown in Figure 12, the support members 3 and suspension members 4 are attached to the beam 2. On each beam 2, the support members 3 and suspension members 4 are arranged at appropriate intervals corresponding to the dimensions of the insulators 5 arranged in the front-to-back direction. 【0038】Next, multiple insulators 5 are attached to the lower part of the beam 2 using the support member 3. For example, the insulators 5 are attached sequentially from one side to the other in the left-right or front-back direction. Figures 13 to 15 show the procedure for attaching the first insulator 5A and the second insulator 5B in this order as an example of attaching two insulators 5 arranged in the left-right direction. In this case, first, as shown in Figure 13, the right-hand first insulator 5A is attached. Specifically, the first insulator 5A is attached to the lower part of the beam 2 by having both the left and right ends of the first insulator 5A supported by the support member 3. Figure 13 shows the situation in which the left end of the first insulator 5A is inserted between the first support portion 33 of the support member 3 and the flange 21 in order to have the left end of the first insulator 5A supported by the support member 3. 【0039】 When the first insulator 5A is installed as described above, the first support portion 33 is inserted between the heat insulating material 51 and the airtight film 52 of the first insulator 5A. That is, as shown in Figure 4, the covering portion 52a of the airtight film 52 that covers the heat insulating material 51 has a first non-adhesive portion Q1 at its left end (first overlapping portion 52a1). The first support portion 33 is inserted between the heat insulating material 51 and the airtight film 52 (covering portion 52a) at the position of this first non-adhesive portion Q1. As a result, the heat insulating material 51 is placed directly on the first support portion 33, and the covering portion 52a is positioned so as to overlap the first support portion 33 from below. 【0040】Next, as shown in Figure 14, the left-side second insulator 5B is attached. Figure 14 shows the situation in which the right end of the second insulator 5B is inserted between the second support portion 34 of the support member 3 and the flange 21 (attached portion 31) for this attachment. At this time, the second support portion 34 is inserted between the heat insulating material 51 and the airtight film 52 of the second insulator 5B. That is, as also shown in Figure 4, the covering portion 52a of the airtight film 52 that covers the heat insulating material 51 has a second non-adhesive portion Q2 at its right end. The second support portion 34 is inserted between the heat insulating material 51 and the airtight film 52 (covering portion 52a) at the position of this second non-adhesive portion Q2. As a result, the heat insulating material 51 is placed directly on the second support portion 34, and the covering portion 52a is positioned so as to overlap the second support portion 34 from below. 【0041】 As previously described, a first excess portion 52b1 is formed at the right end of the airtight film 52 of the second insulator 5B, extending to the right from the heat insulating material 51. As shown in Figure 15, in the state after the second insulator 5B has been installed, this first excess portion 52b1 is positioned to overlap from below the covering portion 52a (first superimposed portion 52a1) of the airtight film 52 of the first insulator 5A, which overlaps the first support portion 33 from below. 【0042】 Once the installation of the first insulator 5A and the second insulator 5B is completed as described above, the boundary between the two insulators 5A and 5B is heated from below, as shown in Figure 15. There are various methods of heating, but in the first embodiment, a heat gun HG is used to apply heat above a predetermined temperature to the boundary. This heating causes the temperature of the first excess portion 52b1 of the second insulator 5B to rise above its melting temperature, causing the first excess portion 52b1 to melt. The melted first excess portion 52b1 becomes integrated with the covering portion 52a of the first insulator 5A. In other words, the first excess portion 52b1 of the second insulator 5B and the covering portion 52a of the first insulator 5A are welded to each other. 【0043】 The installation of the first insulator 5A and the second insulator 5B has been described above, but similar procedures are carried out for other combinations of insulators 5 adjacent to each other in the left-right direction. 【0044】 On the other hand, in the combination of the insulators 5 adjacent in the front-rear direction, the second surplus portion 52b2 of one insulator 5 is overlapped from below with the covering portion 52a of the other insulator 5. For example, as shown in FIG. 7, the second surplus portion 52b2 of the airtight film 52 that projects forward from the front end portion of the heat insulating material 51 of the third insulator 5C is overlapped from below with the rear end portion (the second superimposed portion 52a2) of the covering portion 52a of the airtight film 52 in the first insulator 5A. Heating is also performed on this overlapping portion in the same manner as in FIG. 15. Thereby, the second surplus portion 52b2 and the covering portion 52a are welded to each other. 【0045】 The above operations are repeated until the required number of insulators 5 are laid in the ceiling back space S. Thereby, the insulators 5 are arranged without gaps in the front-rear direction and the left-right direction, and the airtightness and heat insulation of the ceiling back space S are enhanced. Note that the heating of the first surplus portion 52b1 and the second surplus portion 52b2 may be performed collectively on all the insulators 5 after the attachment of all the insulators 5 is completed. 【0046】 After attaching the required number of insulators 5 as described above, or appropriately during the attachment thereof, an operation of attaching an additional airtight film 55 to the installation location of the suspension member 4 is performed. For example, as shown in FIG. 16, an additional airtight film 55 is attached to the suspension member 4 between the first insulator 5A and the second insulator 5B such that the rod screw 43 thereof passes through the additional airtight film 55. The additional airtight film 55 is attached across the lower surfaces of the airtight film 52 of the first insulator 5A and the airtight film 52 of the second insulator 5B. At this time, the additional airtight film 55 adheres to the peripheral surface of the rod screw 43, and the periphery of the rod screw 43 is sealed. 【0047】Incidentally, in the heat insulation construction method as described above, the work shown in FIG. 12 corresponds to the "support member installation step" and the "hanging member installation step" in the present invention, the work shown in FIG. 13 corresponds to the "first support step" in the present invention, the work shown in FIG. 14 corresponds to the "second support step" in the present invention, the work shown in FIG. 15 corresponds to the "welding step" in the present invention, and the work shown in FIG. 16 corresponds to the "attachment step" in the present invention. 【0048】 [Function and Effect] As described above, in the first embodiment, when constructing the first insulator 5A and the second insulator 5B adjacent to each other in the left-right direction in the ceiling space S, after supporting the first insulator 5A on the support member 3 attached to the beam 2, the second insulator 5B is supported on the support member 3 in a state where the airtight film 52 partially overlaps. Specifically, the first surplus portion 52b1 of the airtight film 52 of the second insulator 5B overlaps the covering portion 52a of the airtight film 52 of the first insulator 5A from below, and the second insulator 5B is supported on the support member 3. Then, by applying heat of a predetermined temperature or higher to the first surplus portion 52b1 of the second insulator 5B, the first surplus portion 52b1 is melted and welded to the covering portion 52a of the first insulator 5A. Also, the same operation is performed for the first insulator 5A and the third insulator 5C adjacent to each other in the front-rear direction, and the second surplus portion 52b2 of the third insulator 5C is welded to the covering portion 52a of the first insulator 5A. According to such a method, there is an advantage that the work of enhancing the airtightness and heat insulation of the ceiling portion of the building can be made more efficient. 【0049】In other words, in the first embodiment, when attaching the second insulator 5B to an adjacent position in the left-right direction of the first insulator 5A, the first excess portion 52b1 of the second insulator 5B is superimposed on the covering portion 52a of the first insulator 5A from below. Therefore, by simply heating the first excess portion 52b1 of the second insulator 5B, the first excess portion 52b1 can be welded to the covering portion 52a of the first insulator 5A. Similarly, when attaching the third insulator 5C to an adjacent position in the front-rear direction of the first insulator 5A, the second excess portion 52b2 of the third insulator 5C is superimposed on the covering portion 52a of the first insulator 5A from below. Therefore, by simply heating the second excess portion 52b2 of the third insulator 5C, the second excess portion 52b2 can be welded to the covering portion 52a of the first insulator 5A. This makes it easy to form a continuous airtight line between two adjacent insulators 5 in the left-right or front-back direction, thereby streamlining the process of improving the airtightness and thermal insulation of the ceiling (the space above the ceiling S). 【0050】 Furthermore, in the first embodiment, the first non-adhesive portion Q1 and the second non-adhesive portion Q2 formed at both the left and right ends of the covering portion 52a allow the heat insulating material 51 and the covering portion 52a to be separated. For example, when the first insulator 5A is supported by the support member 3, the first support portion 33 of the support member 3 is inserted between the covering portion 52a and the heat insulating material 51 at the position of the first non-adhesive portion Q1. Similarly, when the second insulator 5B is supported by the support member 3, the second support portion 34 of the support member 3 is inserted between the covering portion 52a and the heat insulating material 51 at the position of the second non-adhesive portion Q2. With this method, the first support portion 33 and the second support portion 34 can be covered and hidden by the covering portion 52a, preventing both support portions 33 and 34 from being exposed below the first insulator 5A. 【0051】Furthermore, in the first embodiment, the first excess portion 52b1 of the second insulator 5B is superimposed from below on the covering portion 52a of the first insulator 5A, which overlaps the first support portion 33 from below. With this method, the first support portion 33 and the covering portion 52a that covers it can be further covered by the first excess portion 52b1, and the excess portion 52b1 can be welded to the covering portion 52a, thereby ensuring that an airtight line is formed at the location where the first support portion 33 is provided. 【0052】 Furthermore, in the first embodiment, the first insulator 5A and the second insulator 5B are arranged adjacent to each other with the suspension member 4 for suspending the ceiling body 6 in between, and after the welding work described above, an additional airtight film 55 is attached to the lower surface of the first insulator 5A and the lower surface of the second insulator 5B with the suspension member 4 inserted through it. With this method, it is possible to ensure good airtightness while realizing the suspension of the ceiling body 6 using the suspension member 4. That is, it is difficult to overlap the airtight films 52 of the first insulator 5A and the second insulator 5B at the installation location of the suspension member 4, but according to the first embodiment in which the additional airtight film 55 with the suspension member 4 inserted is attached to the lower surface of both insulators 5A and 5B, it is possible to ensure good airtightness around the suspension member 4. 【0053】 (2) Figure 17 of the second embodiment is a diagram corresponding to Figure 2 for illustrating the second embodiment of the present invention. In the first embodiment described above, an example was described in which one layer of insulator 5 was installed in the ceiling space S, but it is also possible to install multiple layers of insulator 5. One example of this will be described as the second embodiment. In the following, the differences from the first embodiment will be explained in detail, and other explanations will be omitted or simplified. Also, the same reference numerals will be used for the same components as in the first embodiment. 【0054】As shown in Figure 17, the building in the second embodiment includes a plurality of insulators 500 stacked in two layers, upper and lower, in the space above the ceiling S. That is, the plurality of insulators 500 include a plurality of upper insulators 501 arranged horizontally (front-to-back or left-to-right) and a plurality of lower insulators 502 arranged horizontally below the upper insulators 501. The thickness (vertical dimension) of the upper insulators 501 and lower insulators 502 can be set as appropriate and may be the same or different, but in the second embodiment, the thickness of each insulator 501, 502 is set such that the thickness of the lower insulators 502 is greater than the thickness of the upper insulators 501. 【0055】 Support members 300 are attached to the lower flanges 21 of multiple beams 2 to support the upper insulator 501 and the lower insulator 502 in a stacked state. The support member 300 includes a mounting portion 301 attached to the lower flange 21, an extension portion 302 extending downward from the mounting portion 301, a first support portion 303 and a second support portion 304 extending left and right from the middle of the extension portion 302, and a third support portion 305 and a fourth support portion 306 extending left and right from the lower end of the extension portion 302. The first support portion 303 and the second support portion 304 extend to opposite sides of the extension portion 302 and support the opposing ends of adjacent upper insulators 501 in the left and right direction. The third support portion 305 and the fourth support portion 306 extend to opposite sides of the extension portion 302, supporting the opposing ends of the lower insulators 502 that are adjacent to each other in the left-right direction. 【0056】 As shown in Figure 18, the upper insulator 501 includes a rectangular parallelepiped-shaped thermal insulation material 510 and an airtight film 520 fixed to the lower surface 510f of the thermal insulation material 510 by adhesive. The airtight film 520 has a covering portion 520a that covers the entire lower surface 510f of the thermal insulation material 510 and an excess portion 520b that extends outward from the covering portion 520a. The excess portion 520b has a first excess portion 520b1 that extends to the right (outward) beyond the right surface 510a of the thermal insulation material 510 and a second excess portion 520b2 that extends forward (outward) beyond the front surface 510c of the thermal insulation material 510. 【0057】Similar to the first embodiment described above, the first excess portion 520b1 is overlapped from below and welded to the left end of the covering portion 520a of another upper insulator 501 adjacent to the right. The second excess portion 520b2 is overlapped from below and welded to the rear end of the covering portion 520a of another upper insulator 501 adjacent to the front. In other words, in the second embodiment, excess portions 520b are formed in the airtight film 520 of each upper insulator 501 in order to airtightly seal the space between adjacent upper insulators 501. 【0058】 In the second embodiment, where airtightness is achieved on the lower surface of the upper insulator 501, the first excess portion 520b1 interferes with the extension portion 302 of the support member 300 when the upper insulator 501 is supported by the support member 300. Therefore, as a countermeasure against this interference, in the second embodiment, two cuts extending in the left-right direction are made in the first excess portion 520b1 to form a downward folded portion F1 in the first excess portion 520b1. The folded portion F1 has a width corresponding to the extension portion 302. 【0059】 Specifically, when the upper insulator 501 is supported by the support member 300, the folded portion F1 is folded downward so that it is aligned with the extension portion 302 of the support member 300. At this time, the second support portion 304 of the support member 300 is inserted into the non-adhesive portion Q3 of the covering portion 520a. On the other hand, the first excess portion 520b1 other than the folded portion F1 is overlapped from below and welded to the covering portion 520a of the upper insulator 501 adjacent to it. When the first excess portion 520b1 is heated for this welding, the folded portion F1 is also heated and welded to the extension portion 302. 【0060】 According to the second embodiment described above, a continuous airtight line can be formed between adjacent upper insulators 501 while ensuring higher thermal insulation performance by using two layers of insulators 500 (upper and lower insulators 501, 502) arranged in the ceiling space S. 【0061】In the second embodiment described above, an airtight line was formed on the lower surface of the upper insulator 501 by forming an excess portion 520b in the airtight film 520 of the upper insulator 501. However, instead of this, or in addition, a similar airtight line may be formed on the lower surface of the lower insulator 502. In other words, when multiple layers of insulators stacked vertically are placed in the space above the ceiling, an airtight line only needs to be formed on the lower surface of at least one of the insulator layers, and which layer's lower surface the airtight line is formed on can be appropriately determined according to the construction environment, etc. 【0062】 (3) Summary The embodiments and their variations described above can be summarized as follows. 【0063】 A method according to a first aspect of the present invention is a ceiling insulation construction method for insulating the ceiling of a building, comprising: a preparation step of preparing a first insulating airtight member and a second insulating airtight member, each comprising an insulating material having a lower surface positioned facing the interior of the room, and an airtight film attached to the insulating material, each comprising a covering portion that covers the entire lower surface and an excess portion that extends outward from the lower surface; a support member installation step of installing support members for supporting the first insulating airtight member and the second insulating airtight member at predetermined installation locations; a first support step of supporting the first insulating airtight member on the support members; a second support step of supporting the second insulating airtight member on the support members with the excess portion of the second insulating airtight member overlapping the covering portion of the first insulating airtight member from below; and a welding step of melting the excess portion of the second insulating airtight member by applying heat of a predetermined temperature or higher to the excess portion of the second insulating airtight member and welding it to the covering portion of the first insulating airtight member. 【0064】 According to the first embodiment, when attaching the second insulated airtight member adjacent to the first insulated airtight member, the excess portion of the second insulated airtight member is overlapped from below onto the covering portion of the first insulated airtight member. Therefore, by simply heating the excess portion of the second insulated airtight member, the excess portion can be welded to the covering portion of the first insulated airtight member. This makes it easy to form a continuous airtight line between two adjacent insulated airtight members, and streamlines the process of improving the airtightness and insulation of the ceiling. 【0065】The method according to the second embodiment is, in the first embodiment, the support member has a first support portion that supports the insulation material of the first heat-insulating and airtight member from below, the preparation step is to prepare the first heat-insulating and airtight member in which the airtight film is attached to the insulation material in such a way that the insulation material and the covering portion can be separated in order to insert the first support portion, and the first support step is to support the first heat-insulating and airtight member with the support member in such a way that the first support portion is inserted between the insulation material and the covering portion. 【0066】 According to the second embodiment, the first support portion can be covered and concealed by the covering portion, preventing the first support portion from being exposed beneath the first heat-insulating and airtight member. 【0067】 The method according to the third embodiment is, in the second embodiment, in the second support step, the second heat insulating airtight member is supported by the support member such that the excess portion of the second heat insulating airtight member overlaps from below with the first support portion and the covering portion that overlaps the first support portion from below. 【0068】 According to the third embodiment, the first support portion and the covering portion that covers it can be further covered by the excess portion of the second heat-insulating and airtight member, and the excess portion can be welded to the covering portion of the first heat-insulating and airtight member, thereby ensuring that an airtight line is formed at the location where the first support portion is provided. 【0069】 The method according to the fourth embodiment further includes, in the first to third embodiments, a suspension member installation step prior to the second support step, in which a suspension member for suspending a ceiling surface material is installed below the first and second thermal insulation and airtight members; the second support step further includes supporting the second thermal insulation and airtight member on the support member with a part of the suspension member sandwiched between the thermal insulation material of the first thermal insulation and airtight member and the thermal insulation material of the second thermal insulation and airtight member; and after the welding step, an application step is further included in which another airtight film is applied over the lower surface of the first thermal insulation and airtight member and the lower surface of the second thermal insulation and airtight member with the suspension member inserted through it. 【0070】At the installation location of the suspension member, it is difficult to overlap the airtight films of the first and second insulation and airtight members. In contrast, according to the fourth embodiment, in which another airtight film through which the suspension member is inserted is attached to the lower surface of both insulation and airtight members, good airtightness around the suspension member can be ensured.

Claims

1. A ceiling insulation construction method for insulating the ceiling portion of a building, comprising: a preparation step of preparing a first insulating airtight member and a second insulating airtight member, each comprising an insulating material having a lower surface positioned facing the interior of the room, and an airtight film attached to the insulating material, each comprising a covering portion that covers the entire lower surface and an excess portion that extends to the outside of the lower surface; a support member installation step of installing support members for supporting the first insulating airtight member and the second insulating airtight member at predetermined installation locations; a first support step of supporting the first insulating airtight member on the support members; a second support step of supporting the second insulating airtight member on the support members with the excess portion of the second insulating airtight member overlapping the covering portion of the first insulating airtight member from below; and a welding step of melting the excess portion of the second insulating airtight member by applying heat above a predetermined temperature to the excess portion and welding it to the covering portion of the first insulating airtight member.

2. The ceiling insulation construction method according to claim 1, wherein the support member has a first support portion that supports the insulation material of the first heat-insulating and airtight member from below, the preparation step involves preparing the first heat-insulating and airtight member in which the airtight film is attached to the insulation material in such a way that the insulation material and the covering portion can be separated in order to insert the first support portion, and the first support step involves supporting the first heat-insulating and airtight member with the support member in such a way that the first support portion is inserted between the insulation material and the covering portion.

3. The ceiling insulation construction method according to claim 2, wherein in the second support step, the second heat insulating airtight member is supported by the support member such that the excess portion of the second heat insulating airtight member overlaps the first support portion and the covering portion that overlaps the first support portion from below.

4. A ceiling insulation construction method according to any one of claims 1 to 3, further comprising a suspension member installation step of installing a suspension member for suspending a ceiling surface material below the first and second insulating and airtight members, prior to the second support step, wherein the second insulating and airtight member is supported by the support member with a portion of the suspension member sandwiched between the insulating material of the first insulating and airtight member and the insulating material of the second insulating and airtight member, and after the welding step, an application step of applying another airtight film over the lower surface of the first insulating and airtight member and the lower surface of the second insulating and airtight member with the suspension member inserted through it.

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