JP7468581B2 - Building - Google Patents

Description

The present invention relates to buildings.

As disclosed in Patent Document 1, a conventional building is known that has a roof section that separates an outdoor space from an indoor space, a structural member disposed below the roof section at a distance from the roof section, a heat insulating member provided between the roof section and the structural member, and a moisture-proof member disposed horizontally below the structural member.

In the building, the moisture-proofing member prevents humid air present in the indoor space from moving below the structural members in winter. Therefore, in the building, condensation is prevented from occurring below the structural members in winter.

JP 2021-116560 A

The building described in Patent Document 1 has a problem in that, if the building is constructed in a cold region, etc., condensation may occur near the roof in winter. Specifically, in the building, there is a possibility that humid air that the moisture-proofing member is unable to prevent from flowing in may flow into the vicinity of the roof from below the structural member through gaps in the structural member. Also, in winter in cold regions, etc., cold air from the outdoor space may be transmitted to the roof, causing a significant drop in the temperature of the air near the roof. In this way, if the temperature of the air near the roof has dropped significantly and the above-mentioned humid air flows into the vicinity of the roof, condensation may occur near the roof.

The present invention was made in consideration of the above problems, and its purpose is to provide a building that can prevent condensation from occurring near the roof during the winter in cold regions, etc.

The present invention provides a building comprising a roof section that separates an outdoor space from an indoor space, a structural member that is arranged horizontally below the roof section and away from the roof section, a heat insulating member that is provided between the roof section and the structural member in the vertical direction, a first horizontal airtight member that is arranged horizontally between the structural member and the heat insulating member and that can increase the airtightness between the outdoor space and the indoor space, and a second horizontal airtight member that is arranged horizontally below the first horizontal airtight member across the structural member and that can increase the airtightness between the outdoor space and the indoor space.

According to this building, since the first horizontal airtight member and the second horizontal airtight member are arranged on either side of the structural member, it is possible to suppress the occurrence of condensation near the roof in winter. Specifically, since the second horizontal airtight member is arranged below the structural member in the above building, humid air present in the indoor space is suppressed from flowing from the indoor space to below the structural member. Furthermore, since the first horizontal airtight member is arranged above the structural member in the above building, even if a small amount of humid air that has passed through the second horizontal airtight member flows below the structural member, the air is suppressed from flowing from below the structural member to the vicinity of the roof through gaps in the structural member, etc. In this way, since the above building suppresses the flow of humid air from the indoor space to below the structural member and the flow of humid air from below the structural member to the vicinity of the roof, it is possible to suppress the occurrence of condensation near the roof in winter in cold regions, etc.

In addition, in the above-mentioned building, since the heat insulating member is disposed above the first horizontal airtight member, it is possible to prevent the first horizontal airtight member from being cooled by cold air in the outdoor space. Therefore, when the first horizontal airtight member blocks humid air from below the structural member, it is possible to prevent condensation from occurring near the first horizontal airtight member.

In the above configuration, the structural member may have an upper surface portion extending along the horizontal direction, and the first horizontal airtight member may be disposed on the upper surface portion.

With this configuration, workers can place the first horizontal airtight member on the top surface that extends along the horizontal direction, making it easy to install the first horizontal airtight member along the structural member.

In the above configuration, the structural member may include a plurality of sub-structural members arranged side by side in the horizontal direction, with seams formed between the plurality of sub-structural members, and the first horizontal airtight member may be arranged on the upper surface portion so as to cover at least the seams.

With this configuration, the first horizontal airtight member is arranged to cover at least the joint, so that air that is present below the structural member in winter and contains a small amount of moisture can be prevented from flowing through the joint into the vicinity of the roof portion. Therefore, compared to a case in which the first horizontal airtight member is arranged on the upper surface portion without covering the joint, it is possible to more reliably prevent condensation from occurring near the roof portion in winter.

In the above configuration, the structural member may be made of ALC, and the joint may include a joint filler that is filled into the joint in a wet manner.

With this configuration, the structural members are made of ALC, so the building can be sturdily supported by the structural members. In particular, the roof and its surrounding areas can be sturdily supported by the structural members.

In addition, with this configuration, the joints are filled with a joint filler that is filled in a wet manner, so the joints can be filled without gaps to connect the secondary structural members. Therefore, compared to connecting the secondary structural members in a dry manner (connecting the secondary structural members with gaps formed in the joints), it is possible to more reliably prevent air containing a small amount of moisture that is present below the structural members in winter from flowing through the joints into the vicinity of the roof portion.

In the above configuration, a support member may be further provided to support the roof portion so that a ventilation layer that communicates with the outdoor space is formed between the roof portion and the insulating member.

With this configuration, an air vent layer that communicates with the outdoor space is formed in the area between the roof and the insulating member, so that even if humid air flows into that area in winter, the humid air can be discharged from that area to the outdoor space. This makes it possible to more reliably prevent condensation from occurring in the area between the roof and the insulating member, i.e., in the vicinity of the roof.

The above configuration may further include an exterior wall portion that extends in the vertical direction to be connected to the roof portion and that separates the outdoor space from the indoor space, and a first upper and lower airtight body that is disposed inside the exterior wall portion, extends in the vertical direction to increase airtightness between the outdoor space and the indoor space, and is connected to the first horizontal airtight member.

With this configuration, the first upper and lower airtight bodies can be connected to the first horizontal airtight member, so that air that is present below the structural member in winter and contains a small amount of moisture can be prevented from bypassing the first horizontal airtight member and flowing into the vicinity of the roof section.

In the above configuration, a second upper and lower airtight body may be further provided inside the first upper and lower airtight body, extending in the vertical direction to increase airtightness between the outdoor space and the indoor space, and connected to the second horizontal airtight member.

With this configuration, the second upper and lower airtight bodies can be connected to the second horizontal airtight member, so that humid air present in the indoor space during winter can be prevented from bypassing the second horizontal airtight member and flowing below the structural member.

The present invention provides a building that can prevent condensation from occurring near the roof during the winter in cold regions, etc.

1 is a partial cross-sectional view showing the structure of a building according to one embodiment of the present invention. FIG. 11 is a partial cross-sectional view showing the structure of a building according to a modified embodiment of the present invention.

Below, a description will be given of a building 1 according to one embodiment of the present invention with reference to the drawings. FIG. 1 is a partial cross-sectional view showing the structure of a building 1 according to one embodiment of the present invention. Note that while FIG. 1 shows the up-down and left-right directions (horizontal directions), these directions are shown for the purpose of explaining the building 1 according to this embodiment, and do not limit the structure or manner of use of the building according to the present invention. Also, in FIG. 1, the left side of the paper is shown as the direction toward the outside of the building 1 (outside), and the right side of the paper is shown as the direction toward the inside of the building 1 (inside).

The building 1 according to this embodiment is a steel frame house built in a cold region. As shown in FIG. 1, the building 1 includes a roof portion 10, a structural member 20, a gap adjustment member 30, a heat insulating member 40, a first horizontal airtight member 50, a plurality of support members 60, a plurality of beams 70, a heat insulating moisture barrier 80, a joist 90, a second horizontal airtight member 100, and a ceiling panel material 110. The building 1 also includes an exterior wall portion 120, a panel material 130, a wall-side first heat insulating member 140, a frame body 150, a first upper and lower airtight body 160, a wall-side second heat insulating member 170, a second upper and lower airtight body 180, and an interior wall panel 190.

The roof section 10 divides the outdoor space OS and the indoor space IS. As shown in FIG. 1, the roof section 10 has a waterproof sheet 11 facing the outdoor space OS, a roof insulation member 12 arranged below the waterproof sheet 11, and a planar member 13 arranged below the roof insulation member 12. The waterproof sheet 11 slopes downward as it extends outward, and rainwater that falls on the upper surface of the waterproof sheet 11 or water that is sprinkled thereon is discharged outward. The roof insulation member 12 improves the insulation between the outdoor space OS and the first under-roof space S1. The planar member 13 is made of, for example, plywood. The planar member 13 functions as a member that supports a worker when the worker stands on the roof section 10.

The outdoor space OS is a space located above the roof 10 or to the left (outside) of the exterior wall 120. The indoor space IS is a space located below the roof 10 and to the right (inside) of the exterior wall 120, and includes a first under-roof space S1, a second under-roof space S2, and an indoor space S3. The first under-roof space S1 is a space located near the roof 10 and is a space sandwiched between the roof 10 and the structural member 20 in the vertical direction. The second under-roof space S2 is a space located below the structural member 20 and is a space sandwiched between the structural member 20 and the ceiling panel material 110 in the vertical direction. The indoor space S3 is a space located below the ceiling panel material 110. In this embodiment, an air conditioning unit (not shown) capable of performing cooling and heating operations is installed in the indoor space S3.

The structural member 20 is arranged along the left-right direction at a position below the roof portion 10 and away from the roof portion 10, and has the function of supporting the building 1. It is preferable that the structural member 20 is made of a material capable of sturdily supporting the building 1. For example, the building 1 according to this embodiment uses a structural member 20 made of ALC (Autoclaved Lightweight Aerated Concrete) that meets the standards set forth in JIS A5416. As shown in FIG. 1, the structural member 20 has an upper surface portion 21 that extends along the left-right direction. The structural member 20 according to this embodiment includes sub-structural members 20a that are each made of an ALC panel and arranged side by side in the left-right direction, and the upper surface portion 21 of the structural member 20 is formed by the upper surfaces of the multiple sub-structural members 20a. As shown in FIG. 1, a joint J is formed between the multiple sub-structural members 20a. A joint filler 23 is inserted into the joint J in a wet manner. In this embodiment, the moisture resistance of the joint filler 23 is lower than that of the secondary structural member 20a. As an example, the joint filler 23 is made of mortar.

The gap adjustment member 30 is disposed at the outer end (the left end in FIG. 1) of the structural member 20. As shown in FIG. 1, the gap adjustment member 30 according to this embodiment has an upper surface (reference numeral omitted) that is flush with the upper surface 21 of the structural member 20.

The insulating member 40 is provided between the roof portion 10 and the structural member 20 in the vertical direction, and can improve the insulation between the outdoor space OS and the second under-roof space S2. Specifically, the insulating member 40 according to this embodiment is provided so as to cover the first horizontal airtight member 50 from above at a position away from the roof portion 10 in the vertical direction. As an example, the insulating member 40 is composed of a hard insulating material such as extruded polystyrene foam laminated in three layers. However, the insulating member 40 may also be composed of a fiber-based insulating material such as cellulose fiber, rock wool, or glass wool, and the number of layers constituting the insulating member 40 can be changed as appropriate.

The first horizontal airtight member 50 is disposed between the structural member 20 and the heat insulating member 40 along the left-right direction, and can increase the airtightness between the outdoor space OS and the indoor space IS, more specifically, between the first roof space S1 and the second roof space S2. Specifically, in winter, the second roof space S2 contains a small amount of humid air that the second horizontal airtight member 100 described later was unable to completely suppress from flowing in from the indoor space S3, but the first horizontal airtight member 50 suppresses the air from flowing in from the second roof space S2 to the first roof space S1. In addition, in summer, the outdoor space OS contains air that contains a lot of moisture, but the first horizontal airtight member 50 suppresses the air from flowing in through the first roof space S1 to the second roof space S2. As an example, the first horizontal airtight member 50 is composed of a single resin sheet having moisture resistance. As shown in FIG. 1, the first horizontal airtight member 50 according to this embodiment is disposed on the upper surface 21 of the structural member 20. The first horizontal airtight member 50 is disposed on the upper surface 21 so as to cover at least the seam J. In this embodiment, the first horizontal airtight member 50 is disposed so as to completely cover the upper surface 21 of the structural member 20 and the upper surface of the gap adjustment member 30 in the left-right direction.

Each of the multiple support members 60 supports the roof portion 10 so as to form an air layer V1 between the roof portion 10 and the insulation member 40 that communicates with the outdoor space OS. As shown in FIG. 1, each of the multiple support members 60 has a main body portion 61 including an upper end portion that abuts the roof portion 10 from below, and a seat portion 62 located below the main body portion 61, whose vertical dimension is smaller than the vertical dimension of the main body portion 61 and whose horizontal dimension is larger than the horizontal dimension of the main body portion 61. The seat portion 62 according to this embodiment is fixed to the structural member 20 so as to sandwich the first horizontal airtight member 50 between the upper surface portion 21 in the vertical direction. In other words, in this embodiment, the seat portion 62 in a state in which the first horizontal airtight member 50 is pressed against the upper surface portion 21 is fixed to the structural member 20. Although detailed illustration is omitted, the seat portion 62 is fixed to the structural member 20 by a bolt having a head and a shaft portion. The head is seated on the seat portion 62. The shaft portion penetrates in the vertical direction through a through hole (not shown) formed in the seat portion 62 and a through hole (not shown) formed in the first horizontal airtight member 50, and is screwed into a fastening portion (not shown) provided on the structural member 20. Not limited to this, a fixing means such as a screw having a head and a shaft portion can also be used. In this manner, in this embodiment, since the support member 60 has a seat portion 62 that is fixed to the structural member 20, the worker can easily fix the support member 60 to the structural member 20. In addition, in this embodiment, compared to the case where the main body portion 61 is fixed to the structural member 20, it is not necessary to prepare a bolt having a length that penetrates the main body portion 61 in the vertical direction. The above configuration is suitable for cases where the vertical dimension of the main body portion 61 is large due to circumstances such as the need to arrange the insulation member 40 thick in the vertical direction to sufficiently ensure the insulation performance in the first under-roof space S1.

The ventilation layer V1 exhausts the air present in the first under-roof space S1 to the outdoor space OS via the communication section 131 described below and the ventilation section V2 described below. In winter, the temperature of the air present in the first under-roof space S1 may drop due to the influence of the low-temperature air present in the outdoor space OS, but the ventilation layer V1 of this embodiment is formed in an area of the first under-roof space S1 where the air temperature is particularly likely to drop in winter. Specifically, as shown in FIG. 1, the ventilation layer V1 of this embodiment is formed in an upper area of the first under-roof space S1, in an area close to the roof section 10.

The beams 70 are arranged below the structural member 20 so that each beam supports the structural member 20. The beams 70 include a first beam 70a arranged toward the outside of the building 1 (toward the left side in FIG. 1) and a second beam 70b arranged toward the inside of the building 1 (toward the right side in FIG. 1). As an example, each of the beams 70 is made of an H-shaped steel having a pair of flanges that extend in the left-right direction and face each other in the up-down direction, and a web that extends in the up-down direction so as to connect the middle parts of both flanges in the left-right direction.

The heat insulating moisture barrier 80 is disposed in the second under-roof space S2, and can improve the heat insulating and moisture barrier properties between the first under-roof space S1 and the indoor space S3. As shown in FIG. 1, the heat insulating moisture barrier 80 includes a first heat insulating moisture barrier section 80a, a second heat insulating moisture barrier section 80b, a third heat insulating moisture barrier section 80c, a fourth heat insulating moisture barrier section 80d, and a fifth heat insulating moisture barrier section 80e. Each of the first heat insulating moisture barrier section 80a to the fifth heat insulating moisture barrier section 80e is made of foamed urethane that is applied, for example, by spraying. The first heat insulating moisture barrier section 80a is provided along the inner surface (reference numeral omitted) of the first beam 70a, from the lower surface section 22 of the structural member 20 to the upper surface of the second horizontal airtight member 100. The second heat insulation moisture barrier 80b is provided from the lower surface 22 of the structural member 20 to the upper part of the joist 90 so as to cover the outer side (reference numeral omitted) of the second beam 70b and the outer side of the lower surface (reference numeral omitted) of the flange below the second beam 70b. The third heat insulation moisture barrier 80c is provided from the lower surface 22 of the structural member 20 to the upper part of the joist 90 so as to cover the inner side (reference numeral omitted) of the web of the second beam 70b and the inner side of the lower surface of the flange below the second beam 70b. The fourth heat insulation moisture barrier 80d is provided so as to cover the lower surface 22 of the structural member 20 from the first heat insulation moisture barrier 80a to the second heat insulation moisture barrier 80b. The fifth heat insulation moisture barrier 80e is provided so as to cover the part of the lower surface 22 of the structural member 20 located inside the third heat insulation moisture barrier 80c.

The rafters 90 function as a base material that supports the ceiling board material 110. As shown in FIG. 1, the rafters 90 are arranged below the multiple beams 70 and along the left-right direction.

The second horizontal airtight member 100 is arranged below the first horizontal airtight member 50 along the left-right direction with the structural member 20 in between, and can increase the airtightness between the outdoor space OS and the indoor space IS, more specifically, between the second roof space S2 and the indoor space S3. Specifically, in winter, humid air is present in the indoor space S3 where the heating operation is performed, but the second horizontal airtight member 100 prevents the air from flowing from the indoor space S3 into the second roof space S2. In summer, the second roof space S2 contains a small amount of humid air that the first horizontal airtight member 50 was unable to prevent from flowing in from the outdoor space OS, but the second horizontal airtight member 100 prevents the air from flowing from the second roof space S2 into the indoor space S3. As an example, the second horizontal airtight member 100 is composed of a single resin sheet having moisture resistance. As shown in FIG. 1, the second horizontal airtight member 100 according to this embodiment is provided along the upper surface of the ceiling panel material 110 and is sandwiched between the ceiling panel material 110 and the joist 90. In addition, near the outer periphery as shown in FIG. 1, the second horizontal airtight member 100 is connected to the second upper and lower airtight bodies 180 described later, and is configured to be connected to the first heat insulating moisture barrier 80a sprayed into the second under-roof space S2.

The ceiling board material 110 is composed of a board material such as gypsum board. The ceiling board material 110 is fixed to the rafters 90 via hanging fittings (not shown) that are connected to the second beams 70b, and is arranged along the left-right direction. The ceiling board material 110 has an upper surface (reference number omitted) that vertically sandwiches the second horizontal airtight member 100 between the rafters 90 and the upper surface (reference number omitted) that faces the indoor space S3.

The exterior wall portion 120 extends in the vertical direction so as to be connected to the roof portion 10, and divides the outdoor space OS from the indoor space IS. The exterior wall portion 120 is formed, for example, from an exterior wall panel. The exterior wall portion 120 also has an air vent 121 formed to penetrate the exterior wall portion 120 in the left-right direction. The air vent 121 is formed, for example, from a louver. As shown in FIG. 1, a ventilation section V2 is formed on the inside of the exterior wall portion 120, which communicates with the outdoor space OS through the air vent 121.

The panel material 130 is disposed inside the ventilation section V2 at a position sandwiching the gap adjustment member 30 between the structural member 20 in the left-right direction, and is provided from the upper flange of the first beam 70a to above the roof section 10. The panel material 130 is, for example, a known parapet panel. As shown in FIG. 1, the panel material 130 has a communication section 131 for communicating the ventilation layer V1 and the ventilation section V2. As an example, the communication section 131 is an opening formed to penetrate the panel material 130 in the left-right direction. As a result, in the building 1 according to this embodiment, the air present in the ventilation layer V1 can be discharged to the outdoor space OS through the communication section 131 and the ventilation section V2 (see arrow A in FIG. 1).

The wall-side first insulating member 140 is located inside the ventilation section V2 and below the first beam 70a, and can improve the insulation between the outdoor space OS and the indoor space IS. The wall-side first insulating member 140 is made of a hard insulating material such as extruded polystyrene foam. However, the wall-side first insulating member 140 may also be made of a fiber-based insulating material such as cellulose fiber, rock wool, or glass wool.

The frame 150 is disposed inside the wall-side first insulation member 140 and is fixed to the first beam 70a via a fixing member (not shown). The frame 150 has a pair of horizontal members 150a that extend in the depth direction of the paper surface of FIG. 1 and face each other in the vertical direction, and a pair of vertical members (not shown) that extend in the vertical direction to connect the front ends and rear ends of the pair of horizontal members 150a and face each other in the depth direction. Note that FIG. 1 shows a cross section of the upper horizontal member of the pair of horizontal members 150a. As shown in FIG. 1, the inner surface and the top surface of the upper horizontal member of the pair of horizontal members 150a are covered with the first insulation moisture-proof part 80a.

The first upper and lower airtight body 160 is disposed inside the outer wall portion 120, and extends in the vertical direction to increase the airtightness between the outdoor space OS and the indoor space IS, and is connected to the first horizontal airtight member 50. As shown in FIG. 1, the first upper and lower airtight body 160 according to this embodiment includes a sheet member 161, a connecting member 162, the above-mentioned first beam 70a, and a connecting member 163. The sheet member 161 is, for example, made of a moisture-proof resin sheet, and is disposed so as to extend in the vertical direction at a position sandwiched between the wall-side first insulation member 140 and a pair of vertical members of the frame body 150 in the left-right direction. The connecting member 162 is a member having a substantially U-shaped cross section that is provided to connect the upper end of the sheet member 161 and the first beam 70a while blocking the gap between them in the vertical direction. Specifically, the connecting member 162 has an attached portion (reference numeral omitted) attached to the first beam 70a in an airtight state, a connected portion (reference numeral omitted) directly connected to the sheet member 161 in an airtight state, and a connecting portion (reference numeral omitted) that connects the attached member and the connected portion and has an inner surface covered by the first heat insulating moisture barrier 80a. The connecting member 163 extends in the vertical direction at a position sandwiched between the gap adjustment member 30 and the panel material 130 in the left-right direction, and connects the first beam 70a and the first horizontal airtight member 50 in an airtight state. Specifically, the connecting member 163 has a lower end connected to the upper flange of the first beam 70a and an upper end connected to the outer end of the first horizontal airtight member 50.

The wall-side second insulating member 170 is an insulating material filled inside the frame body 150, and can improve the insulation between the outdoor space OS and the indoor space IS. Specifically, the wall-side second insulating member 170 is an insulating material filled inside the area surrounded by a pair of horizontal members 150a and a pair of vertical members of the frame body 150, and is composed of a fiber-based insulating material such as cellulose fiber, rock wool, or glass wool. However, the wall-side second insulating member 170 may also be composed of a hard insulating material such as extruded polystyrene foam.

The second upper and lower airtight body 180 extends vertically inside the first upper and lower airtight body 160 to increase the airtightness between the outdoor space OS and the indoor space IS, and is connected to the second horizontal airtight member 100. Specifically, the second upper and lower airtight body 180 is disposed between a pair of vertical members of the frame body 150 and the inner wall panel 190, and has an upper end directly connected to the outer end of the second horizontal airtight member 100. As an example, the second upper and lower airtight body 180 is made of a moisture-proof resin sheet.

The inner wall panel 190 is made of a plate material such as gypsum board, and is arranged in the vertical direction at a position inside the second upper and lower airtight body 180. The inner wall panel 190 has an inner surface (reference number omitted) that faces the indoor space S3, and an outer surface (reference number omitted) that faces the second upper and lower airtight body 180.

As described above, according to the building 1 of this embodiment, since the first horizontal airtight member 50 and the second horizontal airtight member 100 are arranged on either side of the structural member 20, it is possible to suppress the occurrence of condensation in the first under-roof space S1 near the roof portion 10 in winter. Specifically, in the above-mentioned building 1, since the second horizontal airtight member 100 is arranged in the second under-roof space S2 below the structural member 20, the air containing moisture present in the indoor space S3 is suppressed from flowing from the indoor space S3 into the second under-roof space S2. Furthermore, since the first horizontal airtight member 50 is arranged above the structural member 20, even if a small amount of air containing moisture that has passed through the second horizontal airtight member 100 flows into the second under-roof space S2, the air is suppressed from flowing from the second under-roof space S2 into the first under-roof space S1 through the gaps in the structural member 20, etc. In this way, in the above-mentioned building 1, the inflow of humid air from the indoor space S3 into the second roof space S2 and the inflow of humid air from the second roof space S2 into the first roof space S1 are suppressed, so that condensation can be suppressed in the first roof space S1 during the winter in cold regions, etc.

In addition, in the building 1 according to this embodiment, the insulating member 40 is disposed above the first horizontal airtight member 50, so that the first horizontal airtight member 50 can be prevented from being cooled by the cold air in the outdoor space OS. Therefore, when the first horizontal airtight member 50 blocks the humid air from the second under-roof space S2, condensation can be prevented from occurring near the first horizontal airtight member 50.

Furthermore, in the building 1 according to this embodiment, a heat insulating and moisture proof body 80 having heat insulating and moisture proof properties is arranged in the second roof space S2 below the structural member 20, so that condensation can be more reliably prevented from occurring in the first roof space S1 near the roof portion 10 during the winter in cold regions, etc.

In addition, in the summer, low-temperature air is present in the indoor space S3 where cooling operation is performed, so if humid air present in the outdoor space OS flows into the indoor space S3, condensation may occur in the indoor space S3. On the other hand, in the building 1 according to this embodiment, the first horizontal airtight member 50 and the second horizontal airtight member 100 are arranged with the structural member 20 in between, so that humid air present in the outdoor space OS is doubly prevented from flowing into the indoor space S3. Therefore, in this embodiment, it is possible to prevent condensation from occurring in the indoor space S3 in the summer.

Furthermore, in the building 1 according to this embodiment, the first horizontal airtight member 50 is disposed above the structural member 20, so that condensation can be prevented from occurring in the second under-roof space S2 below the structural member 20 in the summer. Specifically, in the building 1 according to this embodiment, the first horizontal airtight member 50 prevents humid air present in the outdoor space OS in the summer from flowing from the outdoor space OS into the second under-roof space S2. Therefore, even if low-temperature air flows from the indoor space S3 into the second under-roof space S2, condensation can be prevented from occurring in the second under-roof space S2.

Furthermore, in the building 1 according to this embodiment, the occurrence of condensation in the vicinity of the structural member 20 can be suppressed. Specifically, in this embodiment, a structural member 20 made of ALC is used. In general, ALC is easily cooled, so when a structural member 20 made of ALC is used, if air containing a lot of moisture flows in the vicinity of the structural member 20, condensation may occur in the vicinity of the structural member 20. On the other hand, in this embodiment, the structural member 20 is arranged in a position sandwiched between the first horizontal airtight member 50 and the second horizontal airtight member 100 in the vertical direction, and the inflow of air containing moisture in the vicinity of the structural member 20 is suppressed. Therefore, in this embodiment, the occurrence of condensation in the vicinity of the structural member 20 can be suppressed.

In addition, in the building 1 according to this embodiment, workers can place the first horizontal airtight member 50 on the top surface 21 that extends along the horizontal direction, making it easy to install the first horizontal airtight member 50 along the structural member 20.

In addition, in the building 1 according to this embodiment, the first horizontal airtight member 50 is arranged to cover at least the joint J, so that air containing a small amount of moisture that exists in the second roof space S2 below the structural member 20 in winter can be prevented from flowing into the first roof space S1 near the roof portion 10 through the joint J. Specifically, in this embodiment, an ALC panel is used as the secondary structural member 20a. In general, ALC has a certain degree of moisture resistance. However, in this embodiment, a joint J is formed between the secondary structural members 20a. A joint filling member 23 having a moisture resistance lower than that of the secondary structural member 20a is interposed in the above-mentioned joint J. In this embodiment, the joint J, which may be a path through which moisture-containing air can flow into the first roof space S1, is covered by the first horizontal airtight member 50, so that air containing a small amount of moisture is prevented from flowing into the first roof space S1 through the joint J. Therefore, compared to when the first horizontal airtight member 50 is placed on the upper surface portion 21 without covering the seam J, it is possible to more reliably prevent condensation from occurring in the first under-roof space S1 during the winter.

Furthermore, in the building 1 according to this embodiment, multiple beams 70 are arranged so that each of the upper flanges blocks each of the lower ends of the joints J. In this way, by arranging multiple beams 70 so as to block the entrance of the flow path through which humid air flows into the joints J, the amount of humid air that reaches the first horizontal airtight member 50 can be reduced.

In addition, in the building 1 according to this embodiment, the first horizontal airtight member 50 is arranged to cover at least the joint J, so that it is possible to prevent humid air that flows from the outdoor space OS into the first under-roof space S1 near the roof portion 10 in the summer from flowing into the second under-roof space S2 below the structural member 20 through the joint J. Therefore, compared to a case in which the first horizontal airtight member 50 is arranged on the upper surface portion 21 without covering the joint J, it is possible to more reliably prevent condensation from occurring in the second under-roof space S2 in the summer.

In addition, in the building 1 according to this embodiment, the structural members 20 are made of ALC, so the building 1 can be sturdily supported by the structural members 20. In particular, the roof portion 10 and its surroundings can be sturdily supported by the structural members 20.

In addition, in the building 1 according to this embodiment, the joints J are filled with joint filling members 23 that are filled in a wet manner, so the joints J can be filled without gaps to connect the secondary structural members 20a together. Therefore, compared to connecting the secondary structural members 20a together in a dry manner (connecting the secondary structural members 20a together with gaps formed in the joints J), it is possible to more reliably prevent air that is present below the structural members 20 in winter and contains a small amount of moisture from flowing into the vicinity of the roof portion 10 through the joints J.

In addition, in the building 1 according to this embodiment, a ventilation layer V1 that communicates with the outdoor space OS is formed in the area between the roof 10 and the insulating member 40. Even if humid air flows into this area in winter, the humid air can be discharged from this area to the outdoor space OS. This makes it possible to more reliably prevent condensation from occurring in the area between the roof 10 and the insulating member 40, i.e., in the first under-roof space S1 near the roof 10.

Furthermore, in the building 1 according to this embodiment, a ventilation layer V1 is formed in an area of the first under-roof space S1 near the roof portion 10 where the air temperature is particularly likely to drop in winter. In other words, in winter, when humid air flows in, the ventilation layer V1 is formed in an area of the first under-roof space S1 where condensation is particularly likely to occur. Therefore, in this embodiment, it is possible to more reliably prevent condensation from occurring in the first under-roof space S1.

In addition, in the building 1 according to this embodiment, the first upper and lower airtight bodies 160 are connected to the first horizontal airtight member 50, so that air that is present in the second under-roof space S2 below the structural member 20 in winter and contains a small amount of moisture can be prevented from bypassing the first horizontal airtight member 50 and flowing into the first under-roof space S1 near the roof portion 10.

Furthermore, in the building 1 according to this embodiment, the first upper and lower airtight bodies 160 are connected to the first horizontal airtight member 50, so that the humid air that flows from the outdoor space OS into the first under-roof space S1 near the roof section 10 in summer can be prevented from bypassing the first horizontal airtight member 50 and flowing into the second under-roof space S2 below the structural member 20.

In addition, in the building 1 according to this embodiment, the second upper and lower airtight bodies 180 are connected to the second horizontal airtight member 100, so that humid air present in the indoor space S3 in winter can be prevented from bypassing the second horizontal airtight member 100 and flowing into the second under-roof space S2 below the structural member 20.

Furthermore, in the building 1 according to this embodiment, the second upper and lower airtight bodies 180 are connected to the second horizontal airtight member 100, so that air that is present in the second under-roof space S2 below the structural member 20 during the summer and contains a small amount of moisture can be prevented from bypassing the second horizontal airtight member 100 and flowing into the indoor space S3.

The above describes the building 1 according to one embodiment of the present invention, but the present invention is not limited to this, and the following modified embodiments can be adopted, for example.

(1) In the previous embodiment, the case where the building 1 is a steel frame house has been described, but the present invention is also applicable to the case where the building is a wooden house. Below, with reference to FIG. 2, the building 2 according to the first modified embodiment of the present invention will be described. FIG. 2 is a partial cross-sectional view showing the structure of the building 2 according to the modified embodiment of the present invention. In FIG. 2, the same reference numerals are used for members having the same configuration as in the previous embodiment. The building 2 is a wooden house built in a cold region. Unlike the building 1 according to the previous embodiment, the building 2 includes a structural member 220, a plurality of beams 270, a heat-insulating moisture barrier 280, an exterior wall portion 320, and a first upper and lower airtight body 360.

The structural member 220 is arranged along the left-right direction below the roof portion 10 and away from the roof portion 10, and has the function of supporting the building 2. As with the structural member 220 according to the previous embodiment, the structural member 220 is preferably made of a material capable of sturdily supporting the building 2. For example, the structural member 220 according to this modified embodiment includes a plurality of secondary structural members 220a each made of structural plywood that meets the provisions of Article 6 of the Japanese Agricultural and Forestry Standards for Plywood (last revised February 25, 2014, Ministry of Agriculture, Forestry and Fisheries Notification No. 303). As with the previous embodiment, a first horizontal airtight member 50 is arranged on the upper surface 221 of the structural member 220. The multiple secondary structural members 220a may be made of a surface material such as a structural panel (so-called OSB (Oriented Strand Board)), structural particle board, or structural MDF (Medium Density Fiberboard) that meets the standards set forth in the Japanese Agricultural and Forestry Standards for Structural Panels (last revised November 28, 2013, Ministry of Agriculture, Forestry and Fisheries Notification No. 2904). Alternatively, the multiple secondary structural members 220a may be made of a surface material that has the same strength (bending performance) as each surface material that meets the above standards.

Each of the beams 270 is made of a square timber. As shown in FIG. 2, the beams 270 include a first beam 270a arranged toward the outside of the building 2 (toward the left side of the paper in FIG. 2) and a second beam 270b arranged toward the inside of the building 2 (toward the right side of the paper in FIG. 2).

The heat insulating moisture barrier 280 has a first heat insulating moisture barrier 280a, a second heat insulating moisture barrier 280b, and a third heat insulating moisture barrier 280c. Each of the first heat insulating moisture barrier 280a to the third heat insulating moisture barrier 280c is made of foamed urethane, for example, by spraying. As shown in FIG. 1, the first heat insulating moisture barrier 280a is provided from the lower surface 222 of the structural member 220 to the upper surface of the second horizontal airtight member 100 so as to cover the inner surface (reference numeral omitted) of the first beam 270a. The second heat insulating moisture barrier 280b is provided so as to cover the lower surface 222 of the structural member 220 from the inner surface of the first beam 270a to the outer surface (reference numeral omitted) of the second beam 270b. The third heat insulating moisture barrier 280c is provided so as to cover the portion of the lower surface 222 of the structural member 220 located inside the second beam 270b.

The exterior wall section 320 has an exterior wall material 320a that faces the outdoor space OS, and a wall base plywood 320b that is provided away from the exterior wall material 320a in the inward direction. As shown in FIG. 2, a ventilation section V2 is formed between the exterior wall material 320a and the wall base plywood 320b.

The first upper and lower airtight body 360 includes a sheet member 361 and a connecting member 362. The sheet member 361 has a first portion 361a and a second portion 361b. The first portion 361a extends along the vertical direction at a position inside the wall-side first insulation member 140 and the first beam 270a. The first portion 361a also has an upper end portion that abuts the lower surface portion 222 of the structural member 220. The second portion 361b extends outward from the upper end portion of the first portion 361a at a position sandwiched between the structural member 220 and the first beam 270a in the vertical direction. As an example, the sheet member 361 is composed of a sheet having moisture resistance that is folded so as to have an approximately L-shape in the plan view of FIG. 2. The connecting member 362 extends vertically at a position sandwiched between the structural member 220 and the panel material 130 in the left-right direction, and connects the sheet member 361 and the first horizontal airtight member 50 in a state in which airtightness is maintained. Specifically, the connecting member 362 has a lower end connected to the outer end of the second portion 361b and an upper end connected to the outer end of the first horizontal airtight member 50.

Even in a building 2 having the above-described configuration, condensation can be prevented from occurring in the first under-roof space S1 near the roof portion 10 during the winter.

(2) In the previous embodiment, an example was described in which the structural member 20 includes multiple sub-structural members 20a arranged side by side in the left-right direction, but the present invention is not limited to this. For example, the structural member 20 may include a single sub-structural member 20a. In other words, the structural member 20 may be composed of a single ALC panel. In this case, it is possible to avoid the formation of a seam J between the sub-structural members 20a.

(3) In the previous embodiment, an example was described in which the first horizontal airtight member 50 was arranged to completely cover the upper surface 21 of the structural member 20 and the upper surface of the gap adjustment member 30 in the left-right direction, but the present invention is not limited to this. Specifically, the first horizontal airtight member 50 may be arranged only above the joint J formed between the secondary structural members 20a. Note that, when a gap that allows humid air to pass between the structural member 20 and another member (e.g., the gap adjustment member 30) is formed, it is preferable that the first horizontal airtight member 50 is also arranged above the gap.

(4) In the previous embodiment, the resin sheet sandwiched between the ceiling panel material 110 and the rafter 90 in the vertical direction was treated as the second horizontal airtight member 100, but if a heat insulating moisture barrier 80 is provided in the second roof space S2, the heat insulating moisture barrier 80 may be treated as the second horizontal airtight member 100. Specifically, if the surfaces of each heat insulating moisture barrier portion 80a to 80e of the heat insulating moisture barrier 80 exhibit moisture resistance, and an airtight line that extends in the left-right direction and is connected to the second upper and lower airtight bodies 180 is substantially formed, the heat insulating moisture barrier 80 may be treated as the second horizontal airtight member 100. In this case, it is not necessary to provide a resin sheet between the ceiling panel material 110 and the rafter 90.

(5) In the previous embodiment, an example was described in which the joint J was filled with the joint filling member 23 in a wet manner, but the present invention is not limited to this. For example, the joint J may be provided with a metal fitting that connects the secondary structural members in a dry manner. However, from the viewpoint of preventing the passage of moisture, it is preferable to fill the joint J with the joint filling member 23 in a wet manner and fill the joint J without any gaps.

(6) In the previous embodiment, an example was described in which the first horizontal airtight member 50, which is made of a single resin sheet, is sandwiched between the seat portion 62 and the upper surface portion 21 in the up-down direction. However, the present invention is not limited to this. For example, the first horizontal airtight member 50 may be composed of a plurality of first horizontal airtight pieces (not shown) arranged along the left-right direction between the plurality of support members 60. In this case, the seat portions 62 of each of the plurality of support members 60 sandwich the left-right end portions of each first horizontal airtight piece between the upper surface portion 21.

(7) In the previous embodiment, an example was described in which the seat 62 was fixed to the structural member 20 so as to sandwich the first horizontal airtight member 50 between the seat 62 and the upper surface 21 in the vertical direction. That is, an example was described in which the seat 62 was indirectly fixed to the structural member 20 via the first horizontal airtight member 50. However, the present invention is not limited to this. For example, an opening (not shown) may be formed in the first horizontal airtight member 50 to avoid interference with the seat 62, and the seat 62 may be fixed to the structural member 20 with the seat 62 directly abutting the upper surface 21.

(8) In the previous embodiment, an example was described in which the building 1 has the heat insulating member 40, the first horizontal airtight member 50, the second horizontal airtight member 100, and the heat insulating moisture barrier 80, and the ventilation layer V1 is formed in the first under-roof space S1. However, the present invention is not limited to this, and the combination of the above five configurations can be changed as appropriate. For example, if it is expected that the possibility of condensation occurring in the first under-roof space S1 is relatively low due to circumstances such as the building 1 being constructed in a region other than a cold region, any of the above five configurations may be omitted. As an example, the first horizontal airtight member 50 may be omitted. Even when such a configuration is adopted, the action of the heat insulating member 40, the second horizontal airtight member 100, the heat insulating moisture barrier 80, and the ventilation layer V1 can suppress the occurrence of condensation in the first under-roof space S1 in winter.

(9) In the previous embodiment, an example was described in which the structural member 20 was made of ALC. However, the material of the structural member 20 is not limited to this, and the material of the structural member 20 can be changed as appropriate as long as the same strength (bending performance) as the structural member 20 made of ALC can be ensured.

(10) In the previous embodiment, the heat insulating moisture barrier 80 including the first heat insulating moisture barrier 80a, the second heat insulating moisture barrier 80b, the third heat insulating moisture barrier 80c, the fourth heat insulating moisture barrier 80d, and the fifth heat insulating moisture barrier 80e was described. However, the second heat insulating moisture barrier 80b and the third heat insulating moisture barrier 80c are not essential. For example, the heat insulating moisture barrier 80 may include the first heat insulating moisture barrier 80a and a sixth heat insulating moisture barrier (not shown) provided to cover the inner portion of the first heat insulating moisture barrier 80a on the underside portion 22 of the structural member 20.

Reference Signs 1, 2: Building 10: Roof section 20, 220: Structural member 20a, 220a: Sub-structural member 21, 221: Upper surface section 23: Joint filling member 40: Insulating member 50: First horizontal airtight member 60: Support member 61: Main body section 62: Seat section 100: Second horizontal airtight member 120, 320: Outer wall section 160, 360: First upper and lower airtight bodies 180: Second upper and lower airtight bodies IS: Indoor space J: Joint OS: Outdoor space S1: First under-roof space S2: Second under-roof space S3: Indoor space V1: Ventilation layer

Claims (7)

A building,
A roof portion that separates an outdoor space from an indoor space;
A structural member disposed below the roof portion and spaced apart from the roof portion so as to be aligned in a horizontal direction;
A heat insulating member provided between the roof portion and the structural member in the vertical direction;
a first horizontal airtight member disposed between the structural member and the heat insulating member along a horizontal direction and capable of increasing airtightness between the outdoor space and the indoor space;
a second horizontal airtight member that is disposed below the first horizontal airtight member and horizontally extends across the structural member, and that can enhance airtightness between the outdoor space and the indoor space;
A building that is equipped with the above. The structural member has an upper surface portion extending along a horizontal direction,
The building according to claim 1 , wherein the first horizontal airtight member is disposed on the upper surface portion. The structural member includes a plurality of sub-structural members arranged side by side in a horizontal direction;
a joint is formed between the plurality of sub-structural members;
The building according to claim 2 , wherein the first horizontal airtight member is disposed on the upper surface portion so as to cover at least the joint. The structural member is made of ALC,
4. The building of claim 3, wherein the joints are interposed with a joint filler that is filled in a wet manner. The building according to any one of claims 1 to 4, further comprising a support member that supports the roof portion so that an air layer that communicates with the outdoor space is formed between the roof portion and the insulating member. an exterior wall portion extending in a vertical direction so as to be connected to the roof portion and separating the outdoor space from the indoor space;
The building described in any one of claims 1 to 4, further comprising a first upper and lower airtight body arranged inside the exterior wall portion, extending in the vertical direction to increase airtightness between the outdoor space and the indoor space, and connected to the first horizontal airtight member. The building described in claim 6, further comprising a second upper and lower airtight body extending in the vertical direction inside the first upper and lower airtight body to increase airtightness between the outdoor space and the indoor space and connected to the second horizontal airtight member.