JP7433976B2 - Underfloor flood prevention structure - Google Patents

Description

TECHNICAL FIELD The present invention relates to an underfloor flood prevention structure.

Patent Document 1 listed below discloses a configuration in which a water-absorbing volume-expanding material is provided on the back surface of a draining member. Specifically, a mounting plate constituting a closing portion is attached to the back surface of the draining member, and the closing plate is connected to this mounting plate via a hinge. The water-absorbing volume-expandable material sandwiched between the closing plate and the mounting plate expands when absorbing water, so that the closing plate moves and closes the ventilation path.

Japanese Patent Application Publication No. 2017-008654

However, in the structure described in Patent Document 1, since the material that expands in volume upon water absorption is sandwiched between the closing plate and the mounting plate, the material that expands in volume upon water absorption cannot be easily attached or removed. However, there is room for improvement in ensuring maintainability.

The present invention has been made in consideration of the above-mentioned facts, and an object of the present invention is to provide an underfloor water intrusion prevention structure that can ensure maintainability.

The under-floor flooding prevention structure according to the first aspect includes a foundation flashing provided below the exterior wall material of a building and arranged on the outer peripheral side of the foundation; and a water intrusion prevention member that closes a gap with the foundation drain, and the water intrusion prevention member is formed into a plate shape from a material that is flexible and expands in volume when water is absorbed, and penetrates in the thickness direction of the plate. The main body is provided with a ventilation hole and is curved so that the cross section becomes an arc under no load , and the opening area of the ventilation hole is reduced when the volume of the main body expands due to water absorption.

In the under-floor flooding prevention structure according to the first aspect, a foundation flashing provided below the exterior wall material of the building and placed on the outer periphery of the foundation, and a foundation flashing provided inside the foundation flashing and connecting the foundation and the foundation flashing. The water intrusion prevention member has a plate-shaped main body in which a ventilation hole is formed through the board in the thickness direction, and the main body expands in volume when water is absorbed. It is made of a material that Here, the opening area of the vent hole is reduced when the main body expands in volume due to water absorption. Thereby, in a normal state before the main body absorbs water, air can flow from one surface of the water intrusion prevention member to the other surface through the ventilation hole. On the other hand, when the main body absorbs water, such as when submerged in water, the volume of the main body expands and the opening area of the ventilation hole is reduced. Thereby, it is possible to suppress water from entering from one surface of the water intrusion prevention member to the other surface. Note that the expression "the opening area of the ventilation hole is reduced" broadly includes a state in which the ventilation hole is completely closed.

Further, the main body portion has flexibility. Thereby, the water intrusion prevention member can be attached to the part where water is to be prevented from infiltrating through gaps in the frame or the foundation while the main body is bent. Further, the flood prevention member installed in a narrow space can be removed by hooking a tool or the like onto a vent hole formed in the main body of the flood prevention member and pulling it.

Furthermore , a foundation drain is provided below the exterior wall material of the building, which can prevent rainwater from penetrating through the exterior wall material and into the foundation. Further, a flood prevention member is provided inside the foundation flashing, and the gap between the foundation and the foundation flashing is closed by this flooding prevention member. This allows the gap between the foundation and the foundation flashing to be ventilated during normal times, while preventing water from entering through this gap during flooding. Furthermore, since the main body portion is flexible, the flood prevention member can be easily removed from the gap between the foundation and the foundation flashing.

As explained above, according to the underfloor water intrusion prevention structure according to the present invention, maintainability can be ensured.

FIG. 1 is an enlarged sectional view of a main part of a building to which an underfloor flood prevention structure according to an embodiment is applied. FIG. 2 is an enlarged perspective view showing an enlarged view of the flood prevention member according to the embodiment. 3 is a diagram schematically showing a cross section of the flood prevention member taken along line 3-3 in FIG. 2; (A) shows the normal state before water absorption, and (B) shows expansion due to water absorption. The current state is shown. FIG. 3 is an enlarged perspective view corresponding to FIG. 2 and showing a first modification of the flood prevention member. FIG. 3 is an enlarged perspective view corresponding to FIG. 2 and showing a second modification of the flood prevention member. FIG. 3 is an enlarged perspective view corresponding to FIG. 2 and showing a third modification of the flood prevention member.

Hereinafter, a building 10 to which an under-floor flood prevention structure according to an embodiment is applied will be described with reference to FIGS. 1 to 3.

(Underfloor flood prevention structure)
As shown in FIG. 1, a building 10 is supported on a foundation 12. The foundation 12 of this embodiment is, for example, a cloth foundation.

A floor girder 14 having a substantially U-shaped cross section is provided at the upper end of the foundation 12. The floor girder 14 is made of channel steel, and includes a lower flange 14A extending along the upper end surface of the foundation 12, a web 14B extending upward from the outer end of the lower flange 14A, and a web 14B extending upward from the outer end of the lower flange 14A. The upper flange 14C extends inward from the upper end of the lower flange 14B substantially parallel to the lower flange 14A.

The lower flange 14A extends along the building 10 in the paper plane direction of FIG. 1, and is fixed to the foundation 12 with unillustrated fixtures such as bolts and nuts. Furthermore, a foundation packing 16 is provided in the gap between the foundation 12 and the lower flange 14A of the floor girder 14. A communication hole (not shown) is formed in the foundation packing 16 to communicate between the outside (right side in the figure) and the inside (left side in the figure) of the building 10, and outside air is introduced into the space under the floor through this communication hole. It is composed of

A joist 18 is fixed to the upper part of the upper flange 14C of the floor girder 14. The joists 18 extend in a direction intersecting the extending direction of the floor beams 14 so as to span the adjacent floor beams 14.

Outside the web 14B of the floor beam 14, an exterior wall material 20 is disposed, and the lower end of the exterior wall material 20 is attached to the floor beam 14 by a mounting member 26. Further, the outer wall material 20 extends along the outer periphery of the building 10, and a finishing material 22 is provided on the surface of the outer wall material 20 along the outer wall material 20. Further, a heat insulating member 24 is provided on the back surface of the outer wall material 20 along the outer wall material 20.

Here, a foundation drainer 28 is provided on the lower side of the outer wall surface material 20. The foundation flashing 28 is arranged on the outer peripheral side of the foundation 12 and extends horizontally along the outer wall surface material 20. Furthermore, the base drainer 28 includes a fixed portion 28A, an extending portion 28B, and an arcuate portion 28C.

The fixing portion 28A is superimposed on the back surface of the lower end of the outer wall material 20, and is fixed to the outer wall material 20 with unillustrated fixtures such as bolts and nuts. Furthermore, an extending portion 28B extends from the lower end of the fixing portion 28A toward the outer surface of the outer wall surface material 20. A step is formed in the extending portion 28B, and the outer side is located lower.

A circular arc portion 28C extends downward from the outer end of the extension portion 28B. The arcuate portion 28C is located on the outer side of the building 10 than the foundation 12, and has a substantially arcuate cross-sectional shape that bulges outward. Further, the lower end of the arc portion 28C is located below the upper end of the foundation 12, and the lower end of the arc portion 28C is folded back toward the foundation 12 side. The gap between the outer wall surface material 20 and the foundation 12 is covered by this arc portion 28C. Further, a ventilation path S is provided between the lower end of the arc portion 28C and the foundation 12.

Here, a flood prevention member 30 is disposed inside the base drain 28. The flood prevention member 30 is formed into a substantially rectangular plate shape, and the outer end of the flood prevention member 30 is in contact with the back surface of the arcuate portion 28C in the base drainer 28. Further, the inner end portion of the flood prevention member 30 is in contact with the upper end surface of the foundation 12. As a result, the ventilation path S in the gap between the foundation 12 and the foundation flashing 28 is covered by the flood prevention member 30. Further, a plurality of flood prevention members 30 are arranged along the foundation drain 28, and each flood prevention member 30 has a length of 50 cm to 100 cm. Details of the flood prevention member 30 will be described below.

(Flood prevention member 30)
As shown in FIG. 2, the flood prevention member 30 in this embodiment includes a substantially plate-shaped main body 30A. The main body portion 30A has a substantially rectangular shape when viewed from the thickness direction, and is made of a material that expands in volume when water is absorbed. In this embodiment, as an example, the main body portion 30A is formed of a microcell polymer sheet.

Further, the main body portion 30A is flexible and has a slightly warped shape so that the cross section becomes an arcuate shape in an unloaded state. A plurality of ventilation holes 30B are formed in this main body portion 30A. The ventilation holes 30B are formed at regular intervals in the longitudinal and lateral directions of the main body 30A, and penetrate the main body 30A in the thickness direction. Further, each of the ventilation holes 30B is opened in a substantially square shape with one side of about 5 mm, and all the ventilation holes 30B are formed in substantially the same shape.

Here, the vent hole 30B is configured such that its opening area is reduced when the main body portion 30A expands in volume due to water absorption. Specifically, as shown in FIG. 3A, the main body 30A has a ventilation hole 30B open in the normal state before water absorption, and air from one side of the main body 30A through the ventilation hole 30B. Air can flow to the other side. On the other hand, as shown in FIG. 3B, when the main body 30A absorbs water, such as when submerged in water, the volume of the main body 30A expands and the opening area of the vent hole 30B is reduced. Therefore, the flow of air and water from one surface of the main body portion 30A to the other surface is restricted. For example, the water intrusion prevention member 30 of this embodiment is configured such that the walls of the vent holes 30B come into contact with each other when the main body portion 30A expands in volume due to water absorption, and the vent holes 30B are closed.

(action and effect)
Next, the functions and effects of this embodiment will be explained.

As shown in FIG. 1, in a building 10 to which the under-floor flooding prevention structure of the present embodiment is applied, the foundation flashing 28 can prevent rainwater and the like from penetrating through the exterior wall surface material 20 and into the foundation. In addition, the gap between the foundation 12 and the foundation flashing 28 is closed by a flood prevention member 30 attached inside the foundation flashing 28, and in normal times before the main body portion 30A absorbs water, the foundation 12 and the foundation flashing 28 are closed. Air entering from the ventilation path S between the floor and the floor flows into the space under the floor through the ventilation hole 30B.

On the other hand, the main body part 30A is made of a material that expands in volume when water is absorbed, so when the water intrusion prevention member 30 absorbs water during submergence, the main body part 30A expands in volume and reduces the opening area of the vent hole 30B. Thereby, it is possible to suppress water entering from the ventilation path S from entering inside the water intrusion prevention member 30. In particular, in this embodiment, since the vent hole 30B is closed, water can be effectively stopped by the water intrusion prevention member 30.

Further, in this embodiment, the main body portion 30A of the flood prevention member 30 has flexibility. As a result, as shown by the two-dot chain line in FIG. 1, the flood prevention member 30 is arranged from the ventilation path S between the foundation flashing 28 and the foundation 12 to the inside of the foundation flashing 28 while the main body 30A is bent. can be set. Since the flood prevention member 30 disposed inside the foundation flashing 28 returns to the state before being bent by the restoring force, the flood prevention member 30 can be easily attached.

Furthermore, during maintenance, a tool with an L-shaped tip or the like is inserted through the ventilation path S, hooked onto the ventilation hole 30B formed in the main body part 30A, and pulled downward to prevent water intrusion prevention member 30. can be easily taken out.

As described above, maintainability of the flood prevention member 30 can be ensured. Further, the flood prevention member 30 can be retrofitted to the already constructed building 10 as well. Further, since the flood prevention member 30 of this embodiment is formed to have a length of approximately 50 cm to 100 cm, only the deteriorated water flood prevention member 30 can be taken out and replaced easily. In particular, in this embodiment, since the main body portion 30A is formed of a lightweight microcell polymer sheet that is easy to process, it can be easily cut to the required length. Moreover, since it is lightweight, it does not damage the surrounding outer wall surface material 20 and the like.

Furthermore, as shown in FIG. 2, the flood prevention member 30 of this embodiment has a slightly warped shape so that the cross section becomes an arcuate shape in an unloaded state. As a result, as shown in FIG. 1, one of the mounting surfaces of the flood prevention member 30 is the upper surface of the horizontal foundation 12, and the other mounting surface is extended vertically like the arcuate portion 28C of the foundation drainer 28. Even if it is a surface, the flood prevention member 30 can be stably attached.

Furthermore, since the flood prevention member 30 of this embodiment is entirely formed of a material that expands in volume, when attaching a plurality of flood prevention members 30, a slight gap is left between adjacent flood prevention members 30. Even if it is left open, the gap can be closed when water is absorbed. Therefore, it is not necessary to perform precise positioning when attaching the flood prevention member 30, and work efficiency can be improved.

In addition, in this embodiment, although the structure in which the substantially square ventilation hole 30B was formed in the main body part 30A of the flood prevention member 30 was demonstrated, it is not limited to this. For example, the water intrusion prevention members of the modified examples shown in FIGS. 4 to 6 may be employed. Note that the water intrusion prevention members described in the following first to third modifications are all made of a material that expands in volume when water is absorbed, and are flexible.

(First modification)
As shown in FIG. 4, the flood prevention member 40 according to the first modification includes a substantially plate-shaped main body 40A. The main body portion 40A is formed in a substantially rectangular shape when viewed from the plate thickness direction, and is slightly warped so that the cross section becomes an arc shape in an unloaded state.

Three ventilation holes 40B are formed in the main body portion 40A. Each of the ventilation holes 40B extends from one end in the longitudinal direction of the main body 40A to the other end, and is formed in a slit shape passing through the main body 40A in the thickness direction. Further, the width of the ventilation hole 40B is formed to be approximately 5 mm, and when the volume of the main body portion 40A expands due to water absorption, the opening area of the ventilation hole 40B is reduced.

(Second modification)
As shown in FIG. 5, the flood prevention member 50 according to the second modification includes a substantially plate-shaped main body 50A. The main body portion 50A is formed in a substantially rectangular shape when viewed from the plate thickness direction, and is slightly curved so that the cross section becomes an arc shape in an unloaded state.

A plurality of ventilation holes 50B are formed in the main body portion 50A at intervals in the longitudinal direction. Each of the ventilation holes 50B extends along the lateral direction of the main body 50A, and is formed in a slit shape passing through the main body 50A in the thickness direction. Further, the width of the ventilation hole 50B is formed to be approximately 5 mm, and when the main body portion 50A expands in volume due to water absorption, the opening area of the ventilation hole 50B is reduced.

(Third modification)
As shown in FIG. 6, the flood prevention member 60 according to the third modification includes a substantially plate-shaped main body 60A. The main body portion 60A is formed in a substantially rectangular shape when viewed from the plate thickness direction, and is slightly curved so that the cross section becomes an arc shape in an unloaded state.

A plurality of ventilation holes 60B are formed in the main body portion 60A. The ventilation holes 60B are formed alternately (staggered) when viewed from the thickness direction of the main body 60A, and pass through the main body 60A in the thickness direction. Further, each of the ventilation holes 60B has a substantially circular opening with a diameter of about 5 mm, and when the main body portion 60A expands in volume due to water absorption, the opening area of the ventilation holes 60B is reduced. Even when the flood prevention members according to the first to third variations are employed, the same effects as in this embodiment can be obtained.

Although the flood prevention members 30, 40, 50, and 60 according to the embodiments and modified examples have been described above, it goes without saying that they can be implemented in various forms without departing from the gist of the present invention. For example, in the above embodiment, as shown in FIG. 1, the flood prevention member 30 is installed so as to cover the gap between the foundation 12 of the building 10 and the foundation flashing 28, but the present invention is not limited to this, and the water stops when flooded. It can be widely used in places where it is required.

In addition, although the flood prevention members 30, 40, 50, and 60 according to the above embodiments and modified examples are formed of microcell polymer sheets, they are not limited to this, and may be formed of other materials whose main component is high-performance urethane foam. A formed water intrusion prevention member may also be used. That is, other materials may be used as long as they expand in volume when water is absorbed.

Furthermore, although the flood prevention members 30, 40, 50, and 60 according to the embodiments and modifications described above have a shape that is warped so that the cross section becomes an arc shape in an unloaded state, the present invention is not limited to this. That is, the shape may be changed depending on the location where the flood prevention members 30, 40, 50, and 60 are attached, and the outer shape of the main body portion may be formed into a substantially circular or polygonal shape.

10 Building 12 Foundation 20 Exterior wall material 28 Foundation drainer 30, 40, 50, 60 Flood prevention member 30A, 40A, 50A, 60A Main body 30B, 40B, 50B, 60B Ventilation hole

Claims (2)

A foundation drain provided under the exterior wall material of a building and placed on the outer periphery of the foundation;
a flood prevention member that is provided inside the foundation flashing and closes a gap between the foundation and the foundation flashing;
has
The flood prevention member is made of a flexible material that expands in volume when water is absorbed, and is formed into a plate shape, has a ventilation hole penetrating through the plate in the thickness direction, and has an arcuate cross section in an unloaded state. An underfloor water intrusion prevention structure , comprising a main body section having a warped shape , and an opening area of the vent hole is reduced when the main body section expands in volume due to water absorption. The foundation flashing includes a fixed part superimposed on the back surface of the lower end of the outer wall material, an extending part extending from the lower end of the fixed part toward the outer surface of the outer wall material, and the extending part. A circular arc portion extending downward from the outer end of the projecting portion,
The arcuate portion is located outside the building than the foundation, and has an outwardly bulging cross-sectional shape, and has a lower end located below the upper end of the foundation,
The underfloor flood prevention according to claim 1, wherein the flood prevention member has an outer end in contact with the back surface of the arcuate portion, and an inner end of the flood prevention member in contact with the upper end surface of the foundation. structure.