Foundation drain

Abstract

To prevent rainwater from entering indoor space with a simple structure.SOLUTION: A foundation drain (1) is applied to buildings that have a ventilation channel (40) connecting space under a floor between a building foundation (21) and a foundation (22), and comprises: a draining plate part (12) that extends from the foundation side to exterior side and faces the lower edge of an outer wall; a front plate (13) that hangs down from an outer edge of the draining plate part; and a bottom plate (14) that faces the back of the draining plate part and has a ventilation opening (15) provided within a range between the front plate and the foundation. Further, in a region inner side than the ventilation opening in the bottom plate, a groove (16) for receiving rainwater that rises along the outer wall of the foundation is provided.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a foundation drainage system, and more particularly to a foundation drainage system that is applied to buildings that employ underfloor ventilation construction methods. [Background technology]

[0002] In foundation drains applied to buildings (such as wooden houses) that use underfloor ventilation construction methods, a ventilation opening is provided to send outside air into the underfloor space, as shown in JP 2023-7289 A (Patent Document 1).

[0003] Rainwater that seeps in through the ventilation holes in the foundation gutter can lead to the rotting of the foundation, but since the main function of the foundation gutter is to drain rainwater that runs down the exterior wall surface to the outside, little consideration is given to rainwater seeping in from the ventilation holes into the air duct (the passageway that connects the space under the floor between the building's foundation and the foundation). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2023-7289 A Summary of the Invention [Problem to be solved by the invention]

[0005] Here, during strong winds and rain, the wind and rain that hit the outdoor wall of the building's foundation creates an updraft that runs along the wall. This causes the space between the bottom plate of the foundation skirting and the outdoor wall of the foundation (hereinafter referred to as the "space below the skirting") to become highly pressurized, creating a pressure difference between it and the air passage, which is at normal pressure. This causes the problem that water droplets that adhere to the underside of the bottom plate of the foundation skirting are drawn into the ventilation opening of the foundation skirting and enter the air passage.

[0006] Furthermore, this pressure difference caused rainwater to seep in through the gap between the bottom plate of the foundation drain and the top surface of the foundation.

[0007] The present invention has been made to solve the above-mentioned problems, and its object is to provide a foundation drain that has a simple configuration and is capable of preventing rainwater from entering the indoor space. [Means for solving the problem]

[0008] A foundation flashing according to one aspect of the present invention is a foundation flashing applied to a building having an air passage between the foundation of the building and the foundation that communicates with the underfloor space, and includes a flashing board extending from the foundation side to the exterior and facing the lower end of the exterior wall, a front board hanging down from the exterior end of the flashing board, and a bottom board facing the back surface of the flashing board and having a ventilation opening between the front board and the foundation. A groove is provided in the area of ​​the bottom board that is on the indoor side of the ventilation opening to receive rainwater that flows up along the outdoor wall surface of the foundation.

[0009] Preferably, the groove has an inverted U-shape or a circular arc shape, and the position of the indoor side edge of the groove substantially coincides with the position of the outdoor side wall surface of the foundation.

[0010] Preferably, the foundation further includes a covering portion formed of a first portion disposed at an outdoor corner of the foundation and placed on an upper surface of the foundation, and a second portion extending vertically downward from an outdoor end of the first portion and abutting against an outdoor wall surface of the foundation. The groove portion is provided so as to be continuous with an upper end of the second portion of the covering portion.

[0011] Preferably, the depth of the groove is 8 mm or more, and the width of the groove is 8 mm or more.

[0012] It is preferable that the base drip edge be formed by bending a single thin plate. Effect of the Invention

[0013] According to the present invention, it is possible to prevent rainwater from entering the ventilation passage with a simple structure. Such a foundation water drain is highly versatile and can be applied to many buildings that use underfloor ventilation construction methods. [Brief description of the drawings]

[0014] [Figure 1] A cross-sectional view showing the installation state of a base drip edge according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view of a base drain in accordance with an embodiment of the present invention. [Diagram 3] 1 is a cross-sectional view of a base trim according to an embodiment of the present invention. [Figure 4] A cross-sectional view showing a base trim cutout in accordance with a first modified example of an embodiment of the present invention. [Diagram 5] A cross-sectional view showing a base trim cutout in accordance with a second modified example of an embodiment of the present invention. [Figure 6] FIG. 11 is a cross-sectional view showing a base trim cutout according to embodiment 2 of the present invention. [Figure 7] A cross-sectional view showing a base trim cutout according to variant example 3 of embodiment 2 of the present invention. [Figure 8] This is a diagram showing a schematic diagram of the inflow path of rainwater through a ventilation hole in a typical foundation drain. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference characters and their description will not be repeated.

[0016] <General structure of foundation drainage> Before describing the foundation underside in this embodiment, a general structure of the foundation underside that is applied to buildings (such as wooden houses) that use underfloor ventilation will be described with reference to Fig. 8. Fig. 8 is a cross-sectional view showing the installation state of a general foundation underside 100. In these figures, arrow A1 indicates the upper side of the exterior wall 30, and arrow A2 indicates the outdoor side of the exterior wall 30.

[0017] The base flashing 100 is located below the exterior wall 30 and fixed to the base portion 22. The exterior wall 30 has an air layer 33 between the exterior surface material 31 and the interior surface material 32. The base portion 22 is located above the foundation 21. Between the upper end surface 21a of the foundation 21 and the lower end surface 22a of the base portion 22, an air passage (gap) 40 that communicates with the underfloor space is provided.

[0018] The base drain 100 is composed of a back panel 101 fixed to the outdoor surface of the base 22, a drain panel 102 extending from the lower end of the back panel 101 to the outdoor side, a front panel 103 hanging down from the outdoor end of the drain panel 102, and a bottom panel 104 extending from the lower end of the front panel 103 to the indoor side and facing the back surface (lower surface) of the drain panel 102, and a ventilation hole 105 is provided in the bottom panel 104. The base drain 100 is formed by bending a single thin plate. The base drain 100 is made of metal.

[0019] The back plate portion 101 extends along the vertical direction of the exterior wall 30, and is fixed in a state of surface contact with the outdoor surface of the base portion 22. As shown in the figure, the back plate portion 101 may be fixed via a base rail 23.

[0020] The water dripping plate 102 faces the lower end of the exterior wall 30. Specifically, the water dripping plate 102 is located below the exterior facing material 31 and the ventilation layer 33 of the exterior wall 30. The water dripping plate 102 is gently inclined in the direction of arrow A2, i.e., so that the outdoor side is downward. The position of the outdoor side end of the water dripping plate 102 is closer to the outdoor side than the position of the surface of the exterior facing material 31.

[0021] The front panel 103 is disposed substantially vertically so as to face the air passage 40. The front panel 103 extends below the upper end height of the foundation 21, and its lower end is folded back so as to form a double portion. A folded portion 103a on the back surface of the front panel 103 faces the outdoor surface 21b of the foundation 21 (hereinafter referred to as the "outdoor-side wall surface 21b").

[0022] The bottom plate portion 104 is connected to the upper end of the folded portion 103a of the front plate portion 103 and is disposed approximately horizontally. The indoor side end portion of the bottom plate portion 104 is placed on the upper end surface 21a of the foundation 21. The portion 104' of the bottom plate portion 104 that is placed on the foundation 21 is referred to as the "placement portion 104'." In the attached state, a dry waterproof sealant 52 is provided between the placement portion 104' of the bottom plate portion 104 and the upper end surface 21a of the foundation 21.

[0023] The ventilation opening 105 is a through hole that penetrates the bottom plate portion 104 straight in the plate thickness direction, and is provided within the range between the front plate portion 103 and the foundation 21. During strong winds, as shown by the dashed arrows in FIG. 8, air that collides with the foundation 21 (arrow F11) generates an updraft along the outdoor wall surface of the foundation 21 (arrow F12). This causes water droplets to adhere to the underside of the bottom plate portion, and these water droplets pass through the ventilation opening 105 and may be taken into the internal space 110 of the foundation water cutout 100 (arrow F13). The taken-in outside air passes directly through the air passage 40 and is sent to the underfloor space. The internal space 110 is a space surrounded on three sides by the water cutout plate portion 102, the front plate portion 103, and the bottom plate portion 104.

[0024] As described above, in a typical foundation flashing 100, a lot of wind is blown into the bottom plate 104 where the ventilation opening 105 is located by the rising air current, so the space below the flashing becomes pressurized and becomes higher in pressure than the air passage 40 under normal pressure. Due to this pressure difference, wind, especially rainwater, is likely to be sent from the ventilation passage 105 through the air passage 40 to the underfloor space (arrow F13). In addition, due to the pressure difference, rainwater also enters through the gap between the bottom plate 104 and the upper surface 21a of the foundation (arrow F14). For this reason, in a building to which the foundation flashing 100 is applied, for example, during a relatively strong wind and rain, the rainwater W is likely to enter the air passage 40 through the ventilation opening 105 and the waterproof sealant 52 due to the momentum of the outside air.

[0025] In the following description, a foundation drain equipped with a structure for preventing rainwater from entering will be described. The first embodiment shows a basic structure for preventing rainwater from entering through a ventilation hole, and the second embodiment shows an additional structure for preventing rainwater from entering through a waterproof sealant.

[0026] <Structure of foundation cutout according to the first embodiment> An example of the structure of a base skirting 1 according to this embodiment will be described with reference to Figs. 1 to 3. Fig. 1 is a cross-sectional view showing the installation state of the base skirting 1. Fig. 2 is a perspective view of the base skirting 1, and Fig. 3 is a cross-sectional view of the base skirting 1. In Fig. 2, an arrow A3 indicates the left-right direction (width direction) of the exterior wall 30.

[0027] The basic structure of the base flashing 1 is similar to that of a known base flashing 100, and is made up of a back panel 11 fixed to the outdoor surface of the base 22 (base batten 23), a flashing board 12 extending from the lower end of the back panel 11 to the outdoor side, a front panel 13 hanging down from the outdoor end of the flashing board 12, and a bottom panel 14 extending from the lower end of the front panel 13 to the indoor side and facing the back surface (lower surface) of the flashing board 12, with a ventilation hole 15 provided in the bottom panel 14. Only the parts that differ from the known base flashing 100 will be described in detail below.

[0028] In the foundation drain 1, a groove 16 is provided in the bottom plate 14 in an area (second area R2) on the indoor side of the ventilation opening 15 to receive rainwater that rises along the outdoor wall surface 21b of the foundation 21. The bottom plate 14 has an area (first area R1) between the front plate 13 and the indoor end of the ventilation opening 15, and an area (second area R2) between the indoor end of the ventilation opening 15 and the outdoor wall surface 21 of the foundation.

[0029] The groove portion 16 in this embodiment has an inverted U-shape. That is, the groove portion 16 is formed by bending the second region R2 into an inverted U-shape so that the opening faces downward. Specifically, the groove portion 16 includes a first side portion 16a where a portion P1 continuing to the first region R1 rises upward, an upper surface portion 16c extending from an upper end portion of the first side portion 16a toward the indoor side, and a second side portion 16b extending downward from an indoor side end portion of the upper surface portion 16c.

[0030] In this embodiment, the position of the indoor side edge of the groove 16 is approximately aligned with the position of the outdoor side wall surface of the foundation. Specifically, the second side 16b extends along the vertical extension of the outdoor side wall surface 21b of the foundation 21. That is, the inner surface of the second side 16b of the groove and the outdoor side wall surface 21b are approximately flush with each other. As a result, rainwater carried by the wind blowing in the direction of the dashed arrow F1 is carried upward by the updraft in the direction of the dashed arrow F2, and then is collected in the groove 16.

[0031] As shown in Fig. 2, the ventilation openings 15 are provided at regular intervals along the width direction of the bottom plate portion 14. The grooves 16 are provided linearly in the width direction as indicated by the arrow A3. Rainwater collected in the grooves 16 is guided by the grooves 16 to spread in the width direction and is drained at a position where the wind weakens. This makes it possible to prevent rainwater that hits the outdoor end face of the foundation 21 of the house from entering the air passage 40 through the ventilation openings 15.

[0032] As shown in FIG. 3, the groove 16 is provided in the second region R2, on the outdoor side of the outdoor-side wall surface 21b of the foundation. The depth D1 of the groove 16 is preferably 8 mm or more, and more preferably 10 mm or more and 30 mm or less. The width W of the groove is preferably 8 mm or more, and more preferably 10 mm or more and 30 mm or less. This allows the device to reliably receive rainwater despite its small size, and prevents the rainwater from flowing into the region R1 on the ventilation opening 15 side. This configuration also allows the received wind to be reliably sent in the width direction.

[0033] The distance D2 between the upper surface 16c of the groove and the water drain board 12 is determined taking into consideration the opening area required for ventilation of the underfloor space (an opening with an area of ​​300 cm or more for every 5 m of wall length).

[0034] The base skirting 1 of this embodiment has a simple structure in which a groove 16 is added to a known base skirting 100, and can prevent rainwater W from entering the indoor space, making it highly versatile and applicable to many buildings that use underfloor ventilation construction methods. In addition, because rainwater can be reliably prevented from entering the ventilation passage 40, decay of the base 22 can be prevented.

[0035] Furthermore, the base skirting 1 of this embodiment is also formed by bending a single (metallic) thin plate, similar to the known base skirting 100. Therefore, it is easy to handle and the manufacturing cost can be reduced. Although it is preferable that the base skirting 1 is an integral part, for example, the bottom plate portion 14 may be a separate part.

[0036] <Variations 1-2> In this embodiment, the groove 16 is in an inverted U-shape, but the shape of the groove 16 is not limited to this. Therefore, as shown in Fig. 4, the groove 16A may be formed in an arc shape. Even in this case, it is preferable that the indoor side edge 16d of the groove 16A is provided so as to overlap with the vertical extension line of the outdoor side wall surface 21b of the foundation. Since the groove 16A is in an arc shape, it is possible to flow the received rainwater in the width direction while suppressing energy loss.

[0037] 5, the groove portion 16B may be located within the second region R2, and the indoor side edge 16d of the groove portion may be provided on the outdoor side of the outdoor side wall surface 21b of the foundation. In other words, the second region R2 of the bottom plate portion 14B may have a portion P2 between the indoor side edge 16d of the groove portion and the outdoor side wall surface 21b of the foundation. Even in this case, rainwater that hits the outdoor side end surface of the foundation 21 rises, then moves along the underside of the portion P2 of the bottom plate portion 14, and is contained in the groove portion 16B.

[0038] The base skirting 1 according to this embodiment can prevent rainwater from being drawn into the air passage 40 due to the pressure difference occurring inside and outside the base skirting 1. The base skirting 1 according to this embodiment can reduce the pressure difference between the inside and outside of the ventilation opening 15 because the inside of the groove 16 is pressurized. Also, normally, this pressure difference (between the inside and outside of the ventilation opening) increases as the size of the base skirting 1 decreases, but by employing the base skirting according to this embodiment, it is possible to prevent rainwater from entering. Therefore, the base skirting 1 according to this embodiment can be used more preferably as the size decreases.

[0039] An experiment was also conducted on the above phenomenon. A blower and a water spray were prepared, which were installed 300 mm apart so as to face the outdoor wall surface of the foundation, and the water spray was sprayed 10 times while driving the blower toward the wall surface. The wind speed of the blower was 12 m / s, and the wind speed near the ventilation opening of the conventional base water cutter 100 was 5.37 m / s, whereas the wind speed near the ventilation opening of the base water cutter 1 according to the present embodiment was 4.68 m / s. That is, the base water cutter 1 was able to reduce the wind speed near the ventilation opening 15 by about 20% by providing the groove portion 16. In addition, the amount of moisture adhering to the underside of the first region R1 of the bottom plate portion 14 was 0.18 mg for the conventional base water cutter 100, whereas it was 0.10 mg for the base water cutter 1, and it was found that the groove portion 16 has the effect of reducing the amount of moisture adhering to the first region R1 of the bottom plate portion 14.

[0040] Under the above conditions, the wind speed from the blower was measured at a position 300 mm away in the width direction from the position where the wind from the blower hit the foundation. The wind speed on the bottom plate 14 of the foundation skirting 1 was 1.60 m / s on the underside, while it was 2.85 m / s inside the groove 16. In other words, it was found that the groove 16 receives the wind from the blower and flows it in the width direction.

[0041] <Embodiment 2> Next, a base skirting 1C according to the second embodiment will be described with reference to Fig. 6. The base skirting 1C is disposed at an outdoor corner of the foundation 21 and further includes a covering portion 17 formed of a first portion 17a placed on the upper surface of the foundation and a second portion 17b extending vertically downward from the outdoor end of the first portion 17a and abutting the outdoor wall surface of the foundation 21. The first portion 17a is a mounting portion 14C' of the bottom plate portion, and a waterproof sealant 52 can be interposed between the first portion 17a and the upper surface 21a of the foundation. This can block the intrusion path of rainwater as shown by the arrow F14 in Fig. 8.

[0042] Groove portion 16C is provided so as to be continuous with the upper end of second portion 17b of covering portion 17. For example, second side portion 16b of groove portion 16C is formed without any step between it and second portion 17b of covering portion 17.

[0043] The covering portion 17 is disposed so as to cover the waterproof sealant 52 from above and from the sides. This makes it possible to prevent rainwater from entering the gap between the foundation 21 and the mounting portion 14D' due to a pressure difference, and to prevent rainwater from entering in excess of the capacity of the waterproof sealant 52. In this embodiment, the second portion 17b is formed by hanging down continuously from the second side portion 16b of the groove portion 16C and folding back at its lower end.

[0044] <Modification> FIG. 7 shows a base skirting 1D corresponding to a modified example of the second embodiment. The base skirting 1D is formed so that the upper surface 16c of the groove portion 16D and the mounting portion 14D' of the bottom plate portion 14D are located on approximately the same plane. The through hole 15D is provided at a position lower than the second region R2 and the mounting portion 14D' of the bottom plate portion 14D. This prevents the internal space 10 of the base skirting 1D from becoming smaller, making it easier to ensure the opening area required for ventilation of the underfloor space (an opening with an area of ​​300 cm or more for every 5 m of the wall length), and allows the base skirting 1D to be made smaller.

[0045] It should be noted that the multiple embodiments and modified examples disclosed herein can be applied in combination with each other as necessary.

[0046] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0047] 1,100 Foundation drain, 11 Back panel, 12,102 Drain, 13,103 Front panel, 14,104 Bottom panel, 15,105 Ventilation hole, 16 Groove, 17 Covering, 21 Foundation, 22 Base, 30 Exterior wall, 40 Ventilation channel, 52 Waterproof sealant, W Rainwater.

Claims

1. A foundation water drainage system applied to a building having an air passage between the foundation and the foundation part of the building that communicates with the underfloor space, A water drainage plate portion extending from the base portion side to the outdoor side and facing the lower end portion of the exterior wall; A front plate portion hanging down from an outdoor end portion of the water drainage plate portion; A bottom plate portion facing the back surface of the drainage plate portion and having a ventilation hole provided within a range between the front plate portion and the foundation, A base drainage groove is provided in the bottom plate portion in an area thereof that is indoors relative to the ventilation opening for receiving rainwater that rises along the outdoor wall surface of the foundation.

2. The groove has an inverted U-shape or an arc-shape, The foundation drainage system according to claim 1 , wherein the position of the indoor side edge of the groove is approximately aligned with the position of the outdoor side wall surface of the foundation.

3. a covering portion formed of a first portion that is disposed at an outdoor corner portion of the foundation and placed on an upper surface of the foundation, and a second portion that extends vertically downward from an outdoor end portion of the first portion and abuts against an outdoor wall surface of the foundation; The base flashing according to claim 1 , wherein the groove portion is formed so as to be continuous with an upper end of the second portion of the covering portion.

4. The base flashing according to claim 1, wherein the depth of the groove is 8 mm or more.

5. The base flashing according to claim 1, wherein the width of the groove is 8 mm or more.

6. The base drip-line according to any one of claims 1 to 5, wherein the base drip-line is formed by bending a single thin plate.

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