JP7748271B2 - Top surface rainproofing structure and top surface rainproofing method for building units - Google Patents

Description

This invention relates to a top surface weatherproofing structure and method for a building unit.

Some buildings, such as houses, are made up of modular buildings. These modular buildings are constructed in a short period of time by transporting prefabricated rectangular building units to the construction site and assembling them there (see, for example, Patent Document 1).

In such modular buildings, it is necessary to prevent rainwater from entering the interior of the building units from the time the building units are shipped until the modular building is completed. To achieve this, in Patent Document 1, for example, when it rains, a waterproof sheet large enough to cover the entire top surface of the building unit is placed over the top of the building unit, and the building unit is then shipped from the factory to the construction site.

Japanese Patent Application Publication No. 5-140997

As in Patent Document 1 above, if a building unit is shipped with a waterproof sheet large enough to cover the entire top surface of the building unit when it rains, the waterproof sheet becomes a large component and is therefore difficult to handle. Furthermore, when lifting a building unit at a construction site, at least a portion of the large waterproof sheet must be rolled up in order to attach a lifting device to the building unit. If the building unit is lifted with the waterproof sheet rolled up, there is a risk that rainwater will seep into the building unit through the rolled-up portion of the waterproof sheet.

The main purpose of this invention is to contribute to improving the above-mentioned problems.

In response to the above problems, the present invention provides:
A thin waterproof sheet is provided to cover the thin unwaterproofed portion formed along the upper edge of the building unit;
The water-repellent sheet has a hanging tool insertion hole at both ends, and when the water-repellent sheet covers the non-waterproof portion from above, at least the periphery of the hanging tool insertion hole at both ends is an upper edge contact surface portion that covers the periphery of the upper edge of the building unit in a surface contact state,
A hanger is attached to the building unit through the hanger insertion hole ,
The drainage sheet has cutouts near both ends,
The water-repellent sheet is characterized by a top surface waterproofing structure of the building unit in which the intermediate portion between the cutout portions is installed at a position higher than the upper edge contact surface portion .

According to the present invention, the above-mentioned configuration allows the waterproof sheet to be made smaller and the building unit to be lifted without having to roll up the waterproof sheet.
Furthermore, with the above-described configuration, the draining sheet can be easily and reasonably given different shapes and functions to the middle and both end portions by separating the both end portions from the middle portion by the cutouts.

1 is an overall perspective view of a unit building having a top surface weatherproofing structure according to the present embodiment. FIG. FIG. 2 is an overall perspective view of a lower floor building unit used in the unit building of FIG. 1. This is an enlarged vertical cross-sectional view of a portion of the area around the upper edge of the outer wall of the top floor unit building. 3B is a partially enlarged vertical cross-sectional view of the periphery of the upper edge portion on the opposite side (adjacent side) of FIG. 3A. 3B is a partially enlarged perspective view showing the state in which hangers are attached to both ends of the drain sheet (on the outer wall side) of FIG. 3A. FIG. FIG. 3C is a partially enlarged perspective view showing the state in which hangers are attached to both ends of the draining sheet (adjacent side) of FIG. 3B. 1A is a plan view of both ends of the draining sheet omitting the intermediate portion, FIG. 1B is a vertical cross-sectional view of the vicinity of the hanger insertion holes at both ends of the draining sheet, and FIG. 1C is a vertical cross-sectional view of the outermost portions at both ends of the draining sheet. 10 is a perspective view showing the state in which a water-repellent sheet is attached to the side of a roof panel. FIG. FIG. 10 is a partially enlarged cross-sectional view showing the state in which the water-repellent sheet is attached to the roof panel. FIG. 1 is an enlarged vertical perspective view of both ends of a roof panel with a water-repellent sheet attached. 10 is a perspective view showing the state in which a roof panel with a water-repellent sheet attached is installed on top of a building unit. FIG. FIG. 10 is an enlarged vertical cross-sectional view showing the periphery of the upper edge of a building unit on which a roof panel is installed. This is an oblique view showing the state in which a waterproofing sheet attached to a roof panel is spread over the unwaterproofed area around the upper edge of the building unit. This is a vertical cross-sectional view of the area around the upper edge of the building unit, showing the water-repellent sheet in an unfolded state. FIG. 10 is a partially enlarged perspective view showing the state in which hangers are attached to both ends of the drain sheet from above. 10 is a partially enlarged perspective view of both ends of the drain sheet, showing the state in which the suspender insertion hole to which the suspender is attached is blocked with waterproof tape. FIG. FIG. 10 is a partially enlarged perspective view showing the state in which the drainage sheet is attached to the sheet receiving beam. FIG. 10 is a partially enlarged vertical cross-sectional view showing the state in which the drainage sheet is attached to the sheet receiving beam. FIG. 10 is a partially enlarged perspective view of both ends of the drainage sheet, showing the cutouts being connected with waterproof tape.

Hereinafter, this embodiment will be described in detail with reference to the drawings.
1 to 10D are provided to illustrate this embodiment.

<Configuration> The configuration of this example is explained below.

Buildings such as detached houses and apartment buildings are composed of unit buildings 1 as shown in Figure 1.

The unit building 1 is a building that can be constructed in a short period of time by prefabricating box-shaped (rectangular) building units 2 (Figure 2) in advance at a factory, transporting them to the construction site, and assembling and installing them at the construction site.

The unit building 1 is a multi-story building with a building unit 2 on the upper floor H installed on top of a building unit 2 on the lower floor L. A balcony 3 is also installed on the upper floor H. Note that the building units 2 do not need to be installed vertically 4 in the unit building 1, and the unit building 1 may be a single-story building.

The building unit 2 is a roughly hexahedron with roughly rectangular top and bottom surfaces in plan view and four roughly rectangular side surfaces in side view. The four side surfaces include a pair of parallel side surfaces along the long sides of the building unit 2 and a pair of parallel side surfaces along the short sides.

Exterior walls 5 are attached to the outdoor-facing sides and corners of the unit frame. Note that the exterior walls 5 at the corners may not be shown in the illustration.

The side of the unit frame facing the interior is open. Therefore, the side facing the interior is temporarily covered with a temporary weatherproofing sheet 6. The building unit 2 in Figure 2 is intended to be installed on the lower floor L.

In addition to the basic configuration described above, this embodiment may also have the following configuration:

(1) As shown in Figures 3A to 4B (mainly see Figure 4A), the upper surface weatherproofing structure of the building unit 2 is
A strip of waterproof sheet 13 (FIG. 5) is provided to cover the strip of unwaterproofed portion 12 formed along the upper edge 11 of the building unit 2.
The draining sheet 13 has hanger insertion holes 16 at both ends 14 .
When the water-repellent sheet 13 covers the unwaterproofed portion 12 from above, at least the periphery of the hanging fixture insertion hole 16 at both ends 14 becomes an upper edge contact surface portion 17 that covers the periphery of the upper edge portion 11 of the building unit 2 in a surface contact state.
A hoisting fixture 18 is attached to the building unit 2 through the hoisting fixture insertion hole 16 .

Here, the top surface waterproofing structure of the building unit 2 is a structure for waterproofing the top surface and upper part of the building unit 2. Top surface waterproofing means protecting the top surface and upper part of the building unit 2 from rainwater. Waterproofing can be temporary, performed before the construction of the unit building 1, or permanent, waterproofing, which continues after the construction of the unit building 1; in this example, at least temporary waterproofing is assumed to be possible. Note that it is not limited to temporary waterproofing, and permanent waterproofing may also be possible at the same time.

Temporary weatherstripping is required at least during the period from when the building units 2 are transported from the factory to the construction site during rainfall, when they are installed at the construction site, after the outer shape of the unit building 1 is almost complete, until the roof section is completed. If temporary weatherstripping is not performed, the above work cannot be carried out during rainfall, which will extend the construction period accordingly. This example particularly targets temporary weatherstripping on the top surface or upper part of the building units 2 on the upper floor H (top floor).

The building unit 2 is a unit structure that makes up the unit building 1. As mentioned above, the building unit 2 is roughly rectangular, and has a unit frame with a box-frame rigid frame structure inside. As shown in Figure 2, the unit frame is a box frame with four ceiling beams 2b connected in a rectangular shape between the upper ends of four columns 2a, and four floor beams 2c connected in a rectangular shape between the lower ends of the four columns 2a. Joint pieces 2d are used to connect the columns 2a to the ceiling beams 2b and floor beams 2c, respectively.

The upper edge 11 is the edge portion of the top surface of the building unit 2, which is approximately rectangular in shape, or each side that makes up the top surface, which is approximately rectangular in plan view. The periphery of the upper edge 11 refers to the upper edge 11 and a certain area nearby it.

Specifically, the top surface of the building unit 2 is the inner surface of an area that is approximately rectangular in plan view and is formed by the upper ends of the four columns 2a and the upper surfaces of the four ceiling beams 2b (and the upper surface of the joint piece 2d). The upper edge 11 may include the upper ends of the columns 2a and the upper surfaces of the ceiling beams 2b (and the upper surface of the joint piece 2d). The upper edge 11 may be any of the four ceiling beams 2b, but this example will describe the case where either one of the two ceiling beams 2b that form the long sides of the rectangular top surface is the target.

The non-waterproof portion 12 is the portion of the top surface of the building unit 2 (around the upper edge 11) that has not been waterproofed. The building unit 2 is manufactured in the factory so that almost the entire unit is waterproofed as the waterproof portion 21 (Figure 3A).

At this time, the area along the periphery of the upper edge 11 must be used for lifting the building unit 2, so finishing work to make it waterproof cannot be carried out until installation work at the construction site is complete, and it is left in an unfinished, unwaterproofed state. Note that the unwaterproofed area 12 will be completely waterproofed (fully weatherproofed) when finishing work on the roof is carried out once the rain has stopped after installation of the building unit 2 at the construction site.

The non-waterproof portion 12 is formed along the upper edge 11 with the required width, giving it an elongated shape. The required width is, for example, approximately the same as the width of the ceiling beam 2b, or slightly wider (approximately 2 to 3 times).

The drainage sheet 13 is a thin, flexible, waterproof sheet or film made of a resin such as polyethylene. The drainage sheet 13 is similar to the one installed, for example, as roofing underlayment or on the inside (back side) of a building's exterior wall 5. The drainage sheet 13 has an elongated shape that is at least one size larger in width and length than the unwaterproofed portion 12, so that it can completely cover at least the unwaterproofed portion 12 around the upper edge 11. Therefore, the drainage sheet 13 does not need to be large enough to cover the entire top surface of the building unit 2.

The drainage sheet 13 may have waterproof adhesive tape 22 (Figures 4A, 5, etc.) pre-attached to at least one edge along its extension direction (in this embodiment, the direction of the long side of the building unit 2).

The adhesive tape 22 is attached continuously over almost the entire area of the drainage sheet 13 (for example, up to a position beyond the suspension fitting insertion hole 16), excluding the outermost portions of both ends 14. The adhesive tape 22 is attached to the drainage sheet 13 over at least a length approximately equal to the boundary line between the non-waterproofed portion 12 and the waterproofed portion 21, and is attached so that its extension direction is aligned with the boundary line.

In this embodiment, the adhesive tape 22 is attached so that a portion of it extends beyond one edge of the drainage sheet 13 in the width direction by the required width, and the extending adhesive portion is attached to the boundary line. The boundary line has a length that is approximately the same as or shorter than the long side of the building unit 2. Note that, for example, if the adhesive tape 22 is double-sided tape and attached to the back side of the drainage sheet 13, it will not be necessary to attach it so that a portion of it extends beyond the drainage sheet 13.

Release paper 22a (Figure 5(b)) is attached to the protruding adhesive portion of the adhesive tape 22, and by peeling off the release paper 22a, the water-repellent sheet 13 can be easily attached in the correct position aligned with the boundary line. Note that there is no need to attach adhesive tape 22 to the outermost parts of the water-repellent sheet 13, such as the part that extends beyond the unwaterproofed portion 12 to the outside of the building unit 2 (Figure 5(c)).

The end portions 14 are the terminal portions and surrounding portions on both sides of the elongated drainage sheet 13 in the extension direction (the end portions of the sheet). Specifically, the end portions 14 are the portions that roughly overlap with the columns 2a and joint pieces 2d located on both sides of the long sides of the building unit 2, as well as the portions that are further outward. The end portions 14 also include the portions that extend beyond the long sides of the building unit 2 in the extension direction.

The hanger insertion holes 16 are through-holes formed directly in the upper edge contact surfaces 17 of both ends 14 of the water-repellent sheet 13. The hanger insertion holes 16 are positioned to coincide with mounting holes 23 formed in the upper ends of the pillars 2a of the building units 2, for attaching the hangers 18.

The threaded portion 18a (Figure 4B) provided at the bottom of the sling 18 is passed through the sling insertion hole 16. Therefore, the sling insertion hole 16 has a diameter that is approximately the same as or slightly larger than the threaded portion 18a and the mounting hole 23. One sling insertion hole 16 is provided at each end 14 of the draining sheet 13, approximately in the center of the upper edge contact surface 17. The sling insertion hole 16 is simply an opening. The sling insertion hole 16 is formed in the draining sheet 13 so that it is a hole that is completely exposed to the outside, without, for example, any lid-like attachment to cover the opening.

Reinforcing tape (reinforcing material 24), such as waterproof acrylic tape, may be attached to one or both sides of the portion of the drainage sheet 13 where the hanger insertion hole 16 is formed (upper edge contact surface portion 17). The hanger insertion hole 16 is formed in the same position and size so that it passes through both the drainage sheet 13 and the reinforcing material 24.

In addition, the drain sheet 13 is thicker and flatter at both ends 14 where the reinforcing material 24 is attached, thereby partially improving the adhesion around the suspension insertion holes 16 to the upper edge 11 of the building unit 2. Therefore, the reinforcing material 24 also serves as a component that forms a highly sealing portion of the upper edge contact surface 17. In this embodiment, the reinforcing material 24 is shaped and sized approximately the same as the upper end of the column 2a, and is attached at the position of the upper end of the column 2a, thereby tightly adhering the upper edge contact surface 17 to the upper end of the column 2a.

Covering the upper edge 11 in a surface-to-surface contact state means that most or part of both end portions 14 of the drainage sheet 13 (at least around the hanger insertion holes 16) are placed over the top so that they are in surface contact with the upper end of the column 2a (around the mounting holes 23), the top surface of the joint piece 2d, and the upper surface of the end of the ceiling beam 2b with almost no gaps.

The upper edge contact surface portion 17 is formed on all or part of both end portions 14 of the drainage sheet 13. The upper edge contact surface portion 17 is installed almost horizontally so as to cover from above in a state of almost surface contact with almost horizontal and almost flat surfaces, such as at least the upper end of the column 2a, the upper surface of the joint piece 2d, and the upper surface of the end of the ceiling beam 2b.

As long as the upper edge contact surface 17 has the highest degree of adhesion to at least the upper end of the column 2a, the degree of adhesion in other parts may be somewhat lower. This allows the upper edge contact surface 17 to act as a seal that covers at least the periphery of the mounting hole 23 with almost no gaps, sealing the mounting hole 23.

The hoisting fixtures 18 are auxiliary fixtures that are temporarily attached to the four corners of the top surface of the building unit 2 when the building unit 2 is hoisted using a crane or similar device. There are various types of hoisting fixtures 18, but in this embodiment, as described above, the hoisting fixture 18 has a threaded portion 18a at the bottom and a screw hole 23 that is directly screwed into the mounting hole 23.

The upper part of the hanger 18 is larger than the threaded portion 18a, and the underside has a flat surface that is perpendicular to the threaded portion 18a and surrounds the periphery of the threaded portion 18a. When the hanger 18 is attached to the building unit 2, the underside of the upper part presses against the top surface of the building unit 2 with the upper edge contact surface 17 sandwiched between them, forming a sealing surface that more reliably seals the mounting hole 23.

The hoisting device 18 has a locking portion 18b at its top for engaging the crane hook. The locking portion 18b may be installed in a fixed state relative to the top of the hoisting device 18, or it may be installed so that it is movable. The hoisting device 18 is attached from above to the four corners of the top surface of the building unit 2 when it is shipped from the factory, and is removed from the top surface of the building unit 2 after the building unit 2 is installed at the construction site.

(2) The draining sheet 13 may have cutouts 25 (Figure 4A) near both ends 14, and the middle portion 26 between the cutouts 25 may be positioned higher than the upper edge contact surface portion 17.

Here, the cutouts 25 are cuts made in the drainage sheet 13, and are made in the drainage sheet 13 while leaving the connecting portions 13a so as not to completely separate both end portions 14 from the drainage sheet 13.

The cutouts 25 are formed in the draining sheet 13, extending from the lower edge to the upper edge, generally in the width direction of the sheet, so as not to reach the upper edge. This separates the draining sheet 13 into both end portions 14 and a middle portion 26, allowing for relatively freer shaping. The draining sheet 13 forms a connecting portion 13a around the upper edge of the cutout 25 (almost up to the position where the adhesive tape 22 is applied).

The notch 25 is provided in the waterproof sheet 13 that covers the upper edge 11 (and the surrounding unwaterproofed portion 12) facing the exterior of the unit building 1 (Figure 4A). Alternatively, the notch 25 is provided in the waterproof sheet 13 that is installed on the side to which the exterior wall 5 of the building unit 2 is attached.

On the other hand, the cutouts 25 do not need to be provided in the water-repellent sheet 13 that covers the upper edge 11 (and the surrounding unwaterproofed portion 12) located between adjacent building units 2 (Figure 4B). Furthermore, a thick temporary waterproofing sheet 27 (Figure 3B) may be placed over at least the water-repellent sheet 13 that covers the upper edge 11 located between adjacent building units 2 to provide a double temporary waterproofing means.

In this embodiment, the drainage sheets 13 with cutouts 25 are installed in two locations on the upper floor H of the unit building 1: the unwaterproofed portion 12 facing the balcony 3, and the unwaterproofed portion 12 on the opposite side farthest from the balcony 3 (Figure 1).

The middle portion 26 is the portion between both longitudinal ends 14 of the draining sheet 13 (the middle portion of the sheet). In the case of Figure 4A, the middle portion 26 is the portion (main portion) located between the two cutouts 25 formed on both longitudinal sides of the draining sheet 13.

The middle section 26 occupies most of the longitudinal portion of the drain sheet 13, excluding both end sections 14. The boundary between the middle section 26 and both end sections 14 is located roughly around the boundary between the end of the ceiling beam 2b and the joint piece 2d.

To install the intermediate portion 26 at a position higher than the upper edge contact surface portion 17 means to position the intermediate portion 26 above the upper edge contact surface portion 17 (of both end portions 14).
Since the upper edge contact surface 17 covers the periphery of the upper edge 11 of the building unit 2 in a surface contact state, the middle section 26 is set at a higher position than this. This state can be easily achieved by providing a notch 25 to separate the middle section 26 from the both end sections 14. Preferably, the middle section 26 has a downward-sloping shape as described below.

(3) More specifically, the non-waterproof portion 12 may be formed in an elongated shape along the upper edge 11 by installing a waterproof roof panel 31 (Figure 6A) on top of the building unit 2, shifting it inward from the upper edge 11, as shown in Figure 7A (Figure 7B).
As shown in FIG. 6B (FIG. 6C), the water-repellent sheet 13 may be attached to the side surface 32 of the roof panel 31 facing the non-waterproof portion 12.
As shown in Figures 8A and 8B, the water-repellent sheet 13 may be installed in a downward shape, with the intermediate portion 26 between the cut portions 25 extending from the position of the side surface 32 of the roof panel 31 toward the upper edge portion 11 of the building unit 2.
As shown in Figure 9, the water-repellent sheet 13 may be installed in an L-shape, with both ends 14 having vertical surface portions 34 extending downward along the side surfaces 32 of the roof panel 31 and upper edge contact surface portions 17 extending horizontally along the periphery of the upper edge 11 of the building unit 2.

Here, the roof panels 31 are panels that make up the roof portion of the unit building 1. In this embodiment, the roof panels 31 are installed in a row on top of the building units 2 (at the corners of the top surface) on the upper floor H (top floor), so that the roof portion of the unit building 1 is constructed directly on the building units 2. Because the roof panels 31 are waterproof, most of the top surface of the building units 2 becomes the waterproof portion 21.

Installing the roof panel 31 offset inward from the upper edge 11 means installing the roof panel 31 a required amount toward the inside of the top surface of the building unit 2 so that the roof panel 31 does not cover the mounting holes 23 of the building unit 2.

As a result, the roof panel 31 is installed on the top surface of the building unit 2 so that it does not overlap the upper edge 11 and mounting holes 23 of the building unit 2. Since there is no roof panel 31 above, the top surface of the building unit 2 has an unwaterproofed portion 12, which is a narrow section around the upper edge 11. The unwaterproofed portion 12 is formed with a width equal to the amount of misalignment of the roof panel 31 from the upper edge 11 of the building unit 2 (for example, approximately 2 to 3 times the width of the ceiling beam 2b).

The roof panel 31 can be any type of waterproof panel. For example, as shown in Figures 6A and 6B, the roof panel 31 is constructed by connecting and integrating surface materials 36, such as sheathing boards 36a and waterproof steel base plates 36b, between a pair of parallel roof frames 35, forming a flat surface. The sheathing boards 36a are supported and fixed from below on both sides by braces 36c (Figure 6B) attached to the inside surfaces of the roof frames 35.

The roof frame 35 is a member (side surface forming member) that forms the side surface 32 of the roof panel 31, and is approximately the same length as the long side of the building unit 2. The roof frame 35 located on the outdoor side of each building unit 2 forms the boundary between the unwaterproofed portion 12 and the waterproofed portion 21.

As shown in Figure 7B, the roof frame 35 is a member with an inwardly facing C-shaped cross section, having a vertical web surface 35a and horizontal upper and lower flange surfaces 35b, 35c. The flange surfaces 35b, 35c extend laterally from the upper and lower edges of the web surface 35a toward the inside of the roof panel 31.

On the upper side of the base steel plate 36b, for example, a single solar cell panel 37 or multiple solar cell panels (for example, four panels) are installed along the roof frame 35. The solar cell panel 37 is attached from above to the roof frame 35 (upper flange surface 35b) with screws via mounting brackets 38. At the time of shipment, the solar cell panel 37 is covered on its upper surface with a protective sheet 37a. Furthermore, the solar cell panel 37 is not necessarily required, so it may be omitted, or a dummy panel that resembles the solar cell panel 37 may be used instead.

One or more (e.g., two) roof panels 31 are arranged side by side on the connecting beams 39 and fixed to the connecting beams 39 to form an integrated unit. The multiple roof panels 31 are integrated to form a rectangle with a length approximately the same as the long sides of the building units 2 and a width shorter than the short sides of the building units 2.

The integrated roof panel 31 is then aligned with the top surface of the building unit 2 and installed from above, together with the connecting beam 39, in the center of the top surface of the building unit 2 on the (top) floor H.

The connecting beam 39 is installed at a position roughly at the same level as or slightly below the top surface of the building unit 2. The end 39a of the connecting beam 39 protrudes laterally from the side surface 32 of the roof panel 31 and is secured from above to the ceiling beam 2b of the unit frame, fixed in the vertical direction 4 by fastening devices 39b such as bolts and nuts. The end 39a of the connecting beam 39 is stepped so that it is slightly higher than the main body of the connecting beam 39.

The side surface 32 is the portion of the roof panel 31 located on the outdoor side (panel side surface) and forms the roof frame 35. With the middle portion 26 of the water-repellent sheet 13 aligned with the roof frame 35, the adhesive tape 22 attached to one edge is attached to the roof frame 35 (upper portion) so that it runs continuously over almost the entire length of the roof frame 35.

In this case, the drain sheet 13 is placed with the adhesive tape 22 side facing up. The drain sheet 13 is then attached using the adhesive tape 22 (its protruding adhesive portion) to the upper flange surface 35b of the roof frame 35 or, where the mounting bracket 38 is located, to the upper end surface of the mounting bracket 38. The width of the protruding adhesive portion of the adhesive tape 22 is slightly wider than the width of the upper flange surface 35b of the roof frame 35. Therefore, it is preferable to apply the tip of the protruding adhesive portion of the adhesive tape 22 so that it faces downward by pushing it downward with a tool T, such as a pointed spatula, against the edge of the upper flange surface 35b or the vertical surface of the mounting bracket 38, as shown in Figure 6B.

A downward-sloping shape is when the shape of the middle portion 26 of the water-repellent sheet 13 installed in the unwaterproofed portion 12 slopes downward as a whole from the inside to the outside of the building unit 2. For example, a downward-sloping shape is a shape that does not have any horizontal or reverse-sloping sections. The downward-sloping shape can be any shape as long as the water-repellent sheet 13 slopes downward without rising in the middle. The inside is the indoor side of each building unit 2, and the outside is the outdoor side of each building unit 2.

As a result, the edge of the drain sheet 13 on the inside (roof panel 31 side) is higher and the edge on the outside (top edge 11 side of the building unit 2) is lower, making it less likely for rainwater to accumulate and allowing it to drain outdoors. The middle section 26 of the drain sheet 13 may be shaped in the opposite way to the above, sloping upward from the inside to the outside of the building unit 2, allowing rainwater to drain toward the roof panel 31 side, but a downward sloping shape is preferable.

In this case, the middle section 26 is installed at an angle so that it hangs naturally from the (top of) the side surface 32 of the roof panel 31 toward the upper edge 11 of the building unit 2, as shown in Figure 8B. As a result, the middle section 26 is stretched in a state where it is almost elevated above the unwaterproofed portion 12 of the building unit 2, so that it is higher than the upper edge 11 (spaced stretching section).

The middle section 26 may be stretched tightly to create a continuous, inclined slope with a constant angle, or it may be stretched loosely, as shown on the left side of the figure, to create an uneven slope without a constant angle.

The left side of the figure shows a case in which a waterproof sheet 13 is laid over the unwaterproofed portion 12 formed between adjacent building units 2. In this case, if necessary, a spacing member 40 may be attached to the top of the roof frame 35 to laterally separate the waterproof sheet 13 from the side surface 32 of the roof frame 35. The waterproof sheet 13 is guided almost directly downward from the tip of the spacing member 40, then guided laterally along the top surface of the building unit 2, and installed so that it is aligned with the side surface of the building unit 2 at the upper edge 11. However, at the end 39a of the connecting beam 39, the portion of the waterproof sheet 13 that is guided laterally is exceptionally placed over the end 39a.

The separating members 40 can be left in place and used even after the waterproofing is completed by using sheathing support beams or the like to support the sheathing installed as a connection between the roof panels 31 of adjacent building units 2.

Alternatively, as shown on the right side of the figure, a sheet support beam 41 can be attached to the unwaterproofed portion 12, and part of the width of the middle portion 26 can be supported from below by the sheet support beam 41, thereby raising the middle portion 26 higher than the upper edge portion 11.

One or more sheet support beams 41 are attached on top of the ceiling beams 2b, aligned along the ceiling beams 2b. The sheet support beams 41 are installed so as to be nearly continuous within a range that roughly coincides with the middle portion 26 of the water-repellent sheet 13. However, the sheet support beams 41 may be cut out or divided as necessary in the areas that interfere with the end portions 39a of the connecting beams 39.

By installing the sheet support beam 41, the middle portion 26 is installed so that at least a portion of its width is in contact with the upper surface 41a of the sheet support beam 41 from above. The upper surface 41a of the sheet support beam 41 is inclined downward from the indoor side to the outdoor side. Furthermore, the outdoor-facing portion of the upper surface 41a of the sheet support beam 41 is higher than the line connecting the upper flange surface 35b of the roof frame 35 and the upper edge 11 or the upper end of the exterior wall 5. Therefore, by being supported from below by the sheet support beam 41, the middle portion 26 is reliably formed in a downward shape and is maintained in a raised state so that it is higher than the upper edge 11 relative to the unwaterproofed portion 12 of the building unit 2. The middle portion 26 may be installed so that it is in contact with the entire upper surface 41a of the sheet support beam 41 by loosely tensioning it, or it may be installed so that it is in contact with only a portion by tensioning it.

The right side of the figure shows the case where the middle portion 26 of the waterproofing sheet 13 is laid over the unwaterproofed portion 12 formed on the outdoor side of the unit building 1, where there are no adjacent building units 2. The sheet support beams 41 can be used as support materials for attaching final finishing materials (such as girder covers and gutters) to the roof portion of the unit building 1, and can be left in place and used even after the temporary waterproofing.

In this embodiment, the sheet support beam 41 is a member with a roughly outward C-shaped cross section, with the outdoor side open. As a result, when the middle portion 26 of the drain sheet 13 is loosely stretched, the slope from the top end to where it meets the upper surface 41a of the sheet support beam 41 is relatively steep, the portion where it meets the upper surface 41a of the sheet support beam 41 is gentler, and the portion beyond the sheet support beam 41 is steeper.

The roof panel 31, whose upper surface is a solar panel 37 or the like, is higher than the upper edge 11 of the building unit 2 by at least the thickness of the roof frame 35 (the height of the web surface 35a). The position of the side surface 32 of the roof panel 31 to which the water-repellent sheet 13 is attached may be, for example, above the center of the roof frame 35 in the vertical direction 4, but as mentioned above, it is preferable to attach it to a higher position such as the upper flange surface 35b of the roof frame 35.

9, the vertical surface portions 34 at both end portions 14 of the drain sheet 13 are portions that are above the upper edge contact surface portions 17 and are portions (vertical descending portions) that descend vertically almost directly downward from the upper position (upper flange surface 35b) of the roof frame 35. The vertical surface portions 34 have a length that matches, for example, the height of the side surface 32 of the roof panel 31. Then, by its own weight or by forming an appropriate shape, they are formed into a vertical descending shape that almost follows the side surface 32.
In addition, if a cut-out portion 25 is provided in the drainage sheet 13, the vertical surface portion 34 is formed only at both end portions 14, but if a cut-out portion 25 is not provided in the drainage sheet 13, it may be formed along the entire length of the drainage sheet 13.

The upper edge contact surface 17 is a substantially horizontal surface portion or part thereof formed in the middle of the width direction of both end portions 14 of the water-repellent sheet 13 (below the vertical surface portion 34). The upper edge contact surface 17 has a length that matches the distance from the side surface 32 of the roof panel 31 to the upper edge 11 of the building unit 2. Then, due to its own weight or appropriate bending, it is formed into a horizontal, transverse shape that is substantially aligned with a horizontal surface such as the upper end of the column 2a.

In particular, the hanger insertion hole 16 of the upper edge contact surface portion 17 is aligned with the mounting hole 23. Therefore, by attaching the hanger 18 to the building unit 2 from above through the hanger insertion hole 16, at least a portion of the upper edge contact surface portion 17 is pressed down by the underside of the upper part of the hanger 18, maintaining it in a horizontal position.

The vertical surface portion 34 (vertically descending portion) and the upper edge contact surface portion 17 (horizontal portion) form an L-shape, concave downwards, on both ends 14 as a whole when viewed from the side.

As mentioned above, the drainage sheet 13 installed on the exterior side of the unit building 1 has different shapes at the middle portion 26 and both end portions 14 when installed on the unwaterproofed portion 12, so the difference in height causes the cutouts 25 to open, forming openings 42 at the positions of the cutouts 25. The area around the openings 42 is protected by a local cover 43 provided on the inside (underside) of the drainage sheet 13.

The local cover 43 is a component that locally protects the unwaterproofed portion 12 of the building unit 2 from rainwater that has seeped inside the drainage sheet 13 through the cutout 25.

The local cover 43 is formed by processing a waterproof resin thin plate material. The local cover 43 is installed below the end ends 14 and the middle portion 26 of the drainage sheet 13, a required distance beyond the cutouts 25, and directly covers the periphery of both sides of the non-waterproof portion 12.

The local cover 43 is pre-attached to the roof panel 31 (Fig. 6A). Then, by attaching the roof panel 31 to the top of the building unit 2, the local cover 43 is installed locally on the upper edge 11 of the building unit 2 together with the roof panel 31 (Fig. 8A). The local cover 43 does not have to be specifically connected to the water-repellent sheet 13.

As shown in Figure 6C, the local cover 43 integrally comprises at least a stepped lower surface 43a, a stepped surface 43b, a stepped upper surface 43c, and vertical surface portions 43d and 43e.

The step bottom surface 43a is a rectangular horizontal surface that covers the upper end surfaces of the columns 2a of the building unit 2 and the upper surfaces of the joint pieces 2d from above. The step bottom surface 43a is sized to slightly extend outward from the upper end surfaces of the columns 2a (in the direction of extension of the ceiling beams 2b).

The step upper surface 43c is a rectangular horizontal surface that covers the upper surface 41a of the end of the sheet receiving beam 41 from above (Figure 9).

The step surface 43b is a rectangular vertical surface that connects the step lower surface 43a and the step upper surface 43c. The step surface 43b is approximately the same height as the sheet receiving beam 41. The step surface 43b abuts approximately against the end of the sheet receiving beam 41, preventing the end of the sheet receiving beam 41 from directly hitting the drain sheet 13 and protecting the drain sheet 13 from damage. The step surface 43b is formed, for example, at a distance from the cutout 25 that is approximately the width of the step upper surface 43c or less.

The first vertical surface portion 43d has a length spanning the entire area of the local cover 43 and a height approximately equal to that of the roof frame 35. The lower portion of the vertical surface portion 43d on the sheet receiving beam 41 side is convexly cut out in the shape of the step surface 43b and the step top surface 43c. The vertical surface portion 43d is located on the roof panel 31 side and covers the outer surface of the roof frame 35. In other words, the vertical surface portion 43d is positioned in contact with the outer surface of the web surface 35a of the roof frame 35.

The second vertical surface portion 43e is rectangular and is located on the upper edge portion 11 side of the building unit 2, connecting the step upper surface 43c and the step surface 43b. The vertical surface portion 43e has the same width as the step upper surface 43c and is slightly taller than the step surface 43b.

In addition, a communication hole 43f (Figure 10B) is formed in the step-down surface 43a at a position that coincides with the suspender insertion hole 16 and the mounting hole 23. The communication hole 43f is approximately the same size as the suspender insertion hole 16 and the mounting hole 23, or slightly larger.

Furthermore, the local cover 43 may be provided with a flange portion of a required width along its peripheral edge. For example, the flange portion may be a downward flange 43g formed downward on the edge opposite the stepped surface 43b of the stepped surface 43a or the vertical surface 43d. This downward flange 43g can serve as a drain, etc.

The flange portion may be an inward flange 43h (FIG. 6C) formed laterally on the upper edge of the vertical surface portion 43d. This inward flange 43h serves as an engaging portion or an attachment margin for the upper flange surface 35b of the roof frame 35.
The local cover 43 is fixed to the roof frame 35 with adhesive tape or the like, for example, with the inward flange 43h engaged with the upper flange surface 35b of the roof frame 35 from above.

Furthermore, the lower edges (protruding portions) of the drainage sheet 13 (at both ends 14 and the middle portion 26), which are formed larger than the unwaterproofed portion 12, are temporarily attached to the upper side of the building unit 2 (for example, the column 2a or exterior wall 5) with adhesive tape 44 (Figure 9).

Similarly, the outer portions (extending portions) of the drainage sheet 13 (at both ends 14), which are formed larger than the non-waterproof portion 12, are folded over as appropriate and temporarily secured with adhesive tape 44 (Figure 10A). For example, the protruding portions are attached to the upper side of the building unit 2 (e.g., the outer wall 5 on the short side) or the top surface of the roof panel 31.

(4) Below, we will explain how to waterproof the upper part of the building unit 2.

The method for waterproofing the upper part of the building unit 2 involves the following steps.
A waterproof roof panel 31 is installed on top of the building unit 2, shifted inward from the upper edge 11, to form an unwaterproofed section 12 that extends narrowly along the upper edge 11 (roof panel installation process diagram, Figures 7A and 7B).
The unwaterproofed portion 12 is covered with a thin waterproof sheet 13 attached to the side surface 32 of the roof panel 31 facing the unwaterproofed portion 12 (water-repellent sheet installation step, Figs. 8A and 8B).
At this time, the drain sheet 13 is raised so that the middle portion 26 located between the cutouts 25 provided near both ends 14 is higher than the upper edge 11 relative to the unwaterproofed portion 12 of the building unit 2. The middle portion 26 is then installed in a downward shape from the side surface 32 of the roof panel 31 toward the upper edge 11 of the building unit 2.
In addition, the water-repellent sheet 13 forms a (nearly horizontal) upper edge contact surface 17 by placing both ends 14 located outside the cutout 25 in surface contact with the periphery of the upper edge 11 of the building unit 2 (Figure 9).
Then, a hanger 18 is attached to the building unit 2 through a hanger insertion hole 16 provided in the upper edge contact surface portion 17 of the water-repellent sheet 13 (hanger attachment step, Figure 9).

Here, before the roof panel installation process, the roof panel 31 is placed and fixed onto the connecting beam 39 to form an integrated unit (panel integration process).

Also, as shown in Figure 6A, partial covers 43 are attached to both ends of the side surface 32 of the roof panel 31 in advance (partial cover attachment process).

Then, a thin, long drainage sheet 13 is attached to the roof panel 31 in advance along the side surface 32 (top of the roof frame 35) of the roof panel 31 (drainage sheet attachment process). Either the partial cover attachment process or the drainage sheet attachment process can be performed first.

The drainage sheet 13 has cutouts 25 between both end portions 14 and the middle portion 26. The cutouts 25 may be made before installation, simultaneously with installation, or after installation.

The water-repellent sheet 13 is temporarily folded or rolled up and attached to the top surface or side surface 32 of the roof panel 31 with adhesive tape. This prevents the water-repellent sheet 13 from interfering with the installation of the roof panel 31 to the building unit 2 (water-repellent sheet temporary attachment process).

Then, in the (roof panel installation process), as shown in Figure 7A, the roof panel 31 is installed on top of the building unit 2 using a hanging jig 51 while still integrated with the connecting beams 39. This forms an unwaterproofed portion 12 and a waterproofed portion 21 on the top surface of the building unit 2. Note that the roof panel 31 may also be integrated using the connecting beams 39 immediately before being installed on top of the building unit 2.

After the (roof panel installation process), as shown in Figure 8A, a sheet support beam 41 is attached to a position corresponding to the middle portion 26 along the upper edge 11 (ceiling beam 2b) where the exterior wall 5 of the building unit 2 is attached (sheet support beam attachment process).

In the (water-repellent sheet installation process), the adhesive tape temporarily fastening the sheet to the roof panel 31 is removed, and the sheet 13 is spread over the unwaterproofed portion 12 and hangs down toward the side of the building unit 2. At this time, at the position where the sheet support beam 41 is attached, the middle portion 26, which makes up the majority of the sheet 13, is placed over the sheet support beam 41, thereby raising the sheet 13 higher than the upper edge 11 relative to the unwaterproofed portion 12 of the building unit 2 and installing it in a downward-facing configuration. The lower portion of the middle portion 26 of the sheet 13 is then hung down along the exterior wall 5 on the side of the building unit 2, and the lower edge is attached to the upper part of the exterior wall 5 or the like with adhesive tape 44.

Before the (hanging hardware installation process), the drain sheet 13 has both end portions 14, which are partially separated from the middle portion 26 by the notches 25, hanging almost straight down along the side surface 32 of the roof panel 31 (the outer surface of the roof frame 35) (vertical surface portion 34). Furthermore, both end portions 14 are placed almost horizontally over the top ends of the columns 2a and the top surfaces of the joint pieces 2d (upper edge contact surface portion 17).

Then, the hangers 18 are attached from above to the building unit 2 (mounting holes 23) through the hanger insertion holes 16 (or communication holes 43f) on both ends 14. The lower portions of the drainage sheet 13 are then hung down along the exterior wall 5 on the side of the building unit 2, and the lower edge is attached to the upper portion of the exterior wall 5 with adhesive tape 44.

The above-mentioned processes are carried out at the factory after the building unit 2 is manufactured in order to provide temporary weatherproofing in preparation for rainfall.

(5) Furthermore, the method for waterproofing the upper part of the building unit 2 may include the following steps.
After the building unit 2 has been installed, the hoisting fixture 18 is removed (from the building unit 2) as shown in FIG. 10A (hoisting fixture removal step).
The suspender insertion hole 16 from which the suspender 18 has been removed is sealed with waterproof tape 61 (hole filling process).
As shown in FIG. 10D, the cutouts 25 are connected with waterproof tape 62, and both end portions 14 of the draining sheet 13 are formed downward together with the middle portion 26 (integration step).

Here, in the (hole filling process), the suspension tool insertion hole 16 can be easily sealed by simply applying waterproof tape 61, ensuring reliable waterproofing.

After waterproofing the suspension tool insertion holes 16 with waterproof tape 61 (hole filling process), as shown in Figure 10B, the lower edges of both end portions 14 are temporarily removed from the upper side of the building unit 2 and rolled up to expose the unwaterproofed portions 12. Then, the mounting holes 23 are sealed with waterproof tape 63 from above the communication holes 43f. Alternatively, the local cover 43 can be removed and the mounting holes 23 directly sealed with waterproof tape 63.

At the same time, remove the lower edge of the middle section 26 from the upper side of the building unit 2 and roll it up to expose the unwaterproofed section 12. Then, peel off the release paper 64a from the double-sided tape 64 that was previously attached to the top surface of the sheet support beam 41.

Then, as shown in Figure 10C, the entire water-repellent sheet 13 is hung back over the unwaterproofed portion 12, and the middle portion 26 is attached to the top surface of the sheet-receiving beam 41 using the double-sided tape 64 that was previously attached to the top surface of the sheet-receiving beam 41. The entire lower edge of the water-repellent sheet 13 is then reattached to the side surface 32 of the building unit 2 using adhesive tape 44. In this state, the cutout portion 25 is connected with waterproof tape 62 in the integration process.

In the (integration process), it is preferable to align the middle section 26 and both end sections 14 in a nearly flush state at the cutout 25, and then apply waterproof tape 62 across the two. The waterproof tape 62 is applied continuously along the entire length of the cutout 25. This neatly connects the cutout 25 with the waterproof tape 62, joining the middle section 26 and both end sections 14 together and waterproofing them. Note that because there are no sheet support beams 41 below the end sections 14, even when the end sections 14 are connected to the middle section 26, the end sections 14 will not have exactly the same downward-sloping shape as the middle section 26, but will have a similar downward-sloping shape.

After that, when the rain stops, finishing work is carried out on the roof portion of the unit building 1, waterproofing the unwaterproofed area 12 around the upper edge 11 of the building unit 2 and completing the roof portion. The water-repellent sheet 13 can be left in place or removed depending on the situation.

The above-mentioned processes are carried out after the building unit 2 is installed at the construction site. Waterproof tapes 61-63 are adhesive tapes with waterproof properties.

<Effects> This embodiment provides the following effects:

(Effect 1) The top surface waterproofing structure of the building unit 2 may be provided with a thin, long, non-waterproof portion 12 formed along the upper edge 11 of the building unit 2, and a thin, long, water-repellent sheet 13 that covers the non-waterproof portion 12. This allows the water-repellent sheet 13 to cover only the thin, long, non-waterproof portion 12 formed along the upper edge 11 of the building unit 2. This makes the water-repellent sheet 13 smaller, making it easier to handle.

The drainage sheet 13 may have hanger insertion holes 16 at both ends 14. When the drainage sheet 13 covers the unwaterproofed portion 12 from above, at least the areas around the hanger insertion holes 16 at both ends 14 may form upper edge contact surfaces 17 that cover the periphery of the upper edge 11 of the building unit 2 in a surface-to-surface contact state. A hanger 18 may be attached to the building unit 2 through the hanger insertion holes 16.

As a result, by passing the hanging fixture 18 through the hanging fixture insertion holes 16 provided on both ends 14, the hanging fixture 18 can be attached to the building unit 2 without having to roll up either end 14, even when the unwaterproofed portion 12 of the building unit 2 is still covered with the water-repellent sheet 13.

The upper edge contact surface 17 is placed in surface contact with the upper edge 11 of the building unit 2, creating a seal that leaves almost no gaps through which rainwater can seep in. Therefore, by sealing the periphery of the hanger insertion hole 16 with the upper edge contact surface 17 and then passing a hanger 18 through the hanger insertion hole 16 in this state to close the hole, both ends 14 of the water-repellent sheet 13 can almost reliably prevent rainwater from seeping into the interior of the building unit 2. Furthermore, the hanger 18 can be easily and reliably attached to the building unit 2 while protecting the both ends 14 of the water-repellent sheet 13 from rainwater seepage.

Furthermore, because the hanger insertion holes 16 are pre-formed at both end portions 14 of the water-repellent sheet 13 at the factory, it is possible to accurately form the minimum size of the hanger insertion holes 16 on the building unit 2 (at positions that coincide with the mounting holes 23). Therefore, when the water-repellent sheet 13 is installed along the upper edge 11 of the building unit 2 and the hanger 18 is attached to the building unit 2 through the hanger insertion holes 16, the water-repellent sheet 13 can be installed in a neat and tidy state without waste. Therefore, the upper edge contact surface 17 is formed at both end portions 14 with almost no wrinkles, and the upper edge contact surface 17 can tightly cover the periphery of the hanger insertion hole 16. As a result, the upper edge contact surface 17 acts as a seal that covers at least the periphery of the hanger insertion hole 16, effectively sealing the hanger insertion hole 16.

In addition, reinforcement and waterproofing can be applied in advance around the suspender insertion holes 16 at both ends 14. This increases the strength of the suspender insertion holes 16, making the areas around the suspender insertion holes 16 less likely to tear, and also makes it more difficult for rainwater to penetrate the suspender insertion holes 16. This improves the reliability of the drainage sheet 13.

(Effect 2) In the top surface waterproofing structure of the building unit 2, the water-repellent sheet 13 may have cutouts 25 near both end portions 14. The water-repellent sheet 13 may be installed so that the middle portion 26 between the cutouts 25 is higher than the upper edge contact surface portion 17 (which covers the periphery of the upper edge portion 11 of the building unit 2 in a surface contact state).

As a result, the cutouts 25 separate the end portions 14 from the middle portion 26 of the drainage sheet 13, allowing different shapes and functions to be easily and effortlessly given to the middle portion 26 and both end portions 14. That is, the cutouts 25 allow the upper edge contact surfaces 17 of both end portions 14 to have a shape that is more suitable for attaching the sling 18. Furthermore, the cutouts 25 allow the middle portion 26 to be positioned higher than the upper edge contact surfaces 17, resulting in a shape that makes it easier to drain rainwater. Furthermore, the middle portion 26 and both end portions 14 have fewer wrinkles and tension.

(Effect 3) In the top surface weatherproofing structure of the building unit 2,
The non-waterproof portion 12 may be formed in an elongated shape along the upper edge 11 by installing a waterproof roof panel 31 on the building unit 2, shifting it inward from the upper edge 11.
The water-repellent sheet 13 may be attached to the side 32 of the roof panel 31 facing the unwaterproofed portion 12.

This allows the majority of the upper part of the building unit 2 to be made into a waterproof section 21 by the roof panel 31. Furthermore, the part of the building unit 2 where the roof panel 31 is not installed can be made into a long, narrow, unwaterproof section 12. The unwaterproof section 12 has a long, narrow shape that follows the upper edge 11 of the building unit 2, minimizing its size.

As a result, the draining sheet 13 can be made small and elongated to fit the unwaterproofed portion 12, and the unwaterproofed portion 12 can be easily and reliably covered with just the small draining sheet 13. Furthermore, the compact size makes the elongated draining sheet 13 easier to handle. The draining sheet 13 can be easily installed in the unwaterproofed portion 12 by attaching it to the side surface 32 of the roof panel 31.

The water-repellent sheet 13 may be installed so that the middle portion 26 between the cutouts 25 slopes downward from the side surface 32 of the roof panel 31 toward the upper edge 11 of the building unit 2. Also, both end portions 14 may be installed in an L-shape, with vertical surface portions 34 extending downward along the side surface 32 of the roof panel 31 and upper edge contact surface portions 17 extending horizontally along the periphery of the upper edge 11 of the building unit 2.

This allows the middle section 26 (which makes up the majority of the water-repellent sheet 13) to slope downward from the side 32 of the roof panel 31 toward the upper edge 11 of the building unit 2, thereby promoting the drainage of rainwater.

In addition, by making both end portions 14 of the drainage sheet 13 L-shaped with vertical surface portions 34 and upper edge contact surface portions 17, both end portions 14 can be installed so that they fit neatly along the side surfaces 32 of the roof panel 31 and the upper edge portions 11 of the building units 2. This minimizes gaps through which rainwater can seep in at both end portions 14.

The cutouts 25 allow a single sheet of drainage sheet 13 to be used three-dimensionally, and simultaneously form a middle section 26 suitable for draining rainwater and upper edge contact surfaces 17 on both ends 14 suitable for attaching the hanging fixtures 18.

(Effect 4) The upper part of the building unit 2 is waterproofed by the following method:
A waterproof roof panel (31) is installed on the building unit (2) so as to be offset inward from the upper edge (11), thereby forming an unwaterproofed portion (12) extending in an elongated manner along the upper edge (11);
The non-waterproof portion 12 is covered with a thin water-repellent sheet 13 attached to a side surface 32 of the roof panel 31 facing the non-waterproof portion 12,
The drain sheet 13 is installed in a downward shape from the side 32 of the roof panel 31 toward the upper edge 11 of the building unit 2, with the middle portion 26 located between the cutouts 25 provided near both ends 14 raised so as to be higher than the unwaterproofed portion 12 of the building unit 2, and
The two ends 14 located outside the notch 25 are placed in surface contact with the periphery of the upper edge 11 of the building unit 2 to form an upper edge contact surface 17;
A hanger 18 may be attached to the building unit 2 through a hanger insertion hole 16 provided in the upper edge contact surface 17 of the water-repellent sheet 13.

This allows you to achieve the same effects as above.

(Effect 5) The upper part of the building unit 2 is waterproofed by the following method:
After the building unit 2 is installed, the lifting device 18 is removed (from the building unit 2),
The suspender insertion hole 16 from which the suspender 18 has been removed is sealed with waterproof tape 61,
The cutouts 25 may be connected with waterproof tape 62, so that both end portions 14 of the drain sheet 13 and the middle portion 26 are formed in a downward shape.

As a result, after the hanging fixture 18 is removed, the hanging fixture insertion holes 16 of the drain sheet 13 are blocked, and the entire sheet, including both ends 14, assumes a downward-facing shape, allowing rainwater to be drained from the entire sheet. This allows for the most efficient temporary rainproofing.

2 Building unit 11 Upper edge portion 12 Unwaterproofed portion 13 Water-repellent sheet 14 Both ends 16 Suspension tool insertion hole 17 Upper edge contact surface portion 18 Suspension tool 25 Cutout portion 26 Middle portion 31 Roof panel 32 Side surface 34 Vertical surface portion 61 Waterproof tape 62 Waterproof tape

Claims (4)

A thin waterproof sheet is provided to cover the thin unwaterproofed portion formed along the upper edge of the building unit;
The draining sheet has hanging tool insertion holes at both ends,
When the drainage sheet covers the unwaterproofed portion from above, at least the periphery of the hanging tool insertion hole at both ends serves as an upper edge contact surface portion that covers the periphery of the upper edge of the building unit in a surface contact state,
A hanger is attached to the building unit through the hanger insertion hole ,
The drainage sheet has cutouts near both ends,
A top surface rainproofing structure for a building unit , characterized in that the water-repellent sheet is installed at a position where the intermediate portion between the cutout portions is higher than the upper edge contact surface portion . The top surface weatherproofing structure of the building unit according to claim 1 ,
The non-waterproof portion is formed in an elongated shape along the upper edge by installing a waterproof roof panel on the building unit and offsetting it inward from the upper edge,
The water-repellent sheet is attached to the side of the roof panel facing the unwaterproofed portion,
The drainage sheet is installed such that the middle portion extends downward from the side of the roof panel to the upper edge of the building unit, and
The upper surface rainproofing structure of a building unit is characterized in that both ends are installed in an L-shape having a vertical surface portion extending downward along the side of the roof panel and an upper edge contact surface portion extending horizontally along the periphery of the upper edge of the building unit. A waterproof roof panel is installed on the building unit, offset from the upper edge toward the inside, to form an unwaterproofed portion extending in a narrow strip along the upper edge;
The unwaterproofed portion is covered with a thin, long water-repellent sheet attached to the side of the roof panel facing the unwaterproofed portion,
The drainage sheet is installed in a downward shape from the side of the roof panel toward the upper edge of the building unit, with the middle portion located between the cutouts provided near both ends raised higher than the upper edge portion relative to the unwaterproofed portion of the building unit, and
The two ends located outside the notches are placed in surface contact with the periphery of the upper edge of the building unit to form an upper edge contact surface;
A method for waterproofing the top surface of a building unit, characterized in that a hanger is attached to the building unit through a hanger insertion hole provided in the upper edge contact surface portion of the water-repellent sheet. 4. The method for waterproofing a top surface of a building unit according to claim 3 ,
After the building unit is installed, the lifting device is removed;
The suspender insertion hole from which the suspender has been removed is sealed with waterproof tape,
A method for waterproofing the top surface of a building unit, characterized in that the cut-out portions are connected with the waterproof tape, and both ends of the drainage sheet are formed into a downward-facing shape together with the middle portion.