JP6864446B2 - Underfloor insulation structure - Google Patents

Description

The present invention relates to an underfloor heat insulating structure that reduces heat escaping to the outside from the periphery of a frame-shaped outer peripheral foundation that supports a building.

In order to enhance the comfort of a building such as a house or a building, it has been proposed to enhance the heat insulation of the underfloor space of the building (see Patent Document 1 and the like).

For example, in order to enhance the heat insulating property of the frame-shaped outer peripheral foundation that supports the building, as shown in FIG. 3 (b), which is an external perspective view of FIG. 3 (a) and a partial sectional view thereof, the ground (ground G, It is known that a heat insulating material 2 made of foamed polyethylene or the like is attached to the inner surface of the outer peripheral portion (rising portion 1A) of the foundation projecting from the ground level (GL) at its height.

Note that FIG. 3 shows the case of the cloth foundation 1, and a footing portion 1B (also referred to as a base portion or a bottom plate) overhanging in a substantially horizontal direction is formed in the ground below the rising portion 1A of the foundation. .. In addition, the ground inside the foundation (soil D, its height is the soil level: DL) is filled so as to be higher than the ground (GL) around the foundation using the excavated soil for the foundation. A moisture-proof soil concrete layer 3 is cast on the upper surface of the embankment via a moisture-proof sheet (not shown) or the like.

The heat insulating material 2 disposed inside the rising portion 1A has a flat plate shape (straight shape or an I-shaped cross section) along the vertical surface inside the rising portion 1A, and has a soil floor as shown in FIG. 3 (b). In addition to the case where it is arranged only above the concrete layer 3, two heat insulating materials 2 as shown in FIG. 3C are used, and these are formed from the inner surface of the rising portion 1A to the edge of the soil concrete layer 3. When arranged in a substantially L-shaped cross section continuous along the upper surface, or as shown in FIG. 3D, a heat insulating material is added before the soil concrete layer 3 is placed, and the heat insulating material 2 is provided. , From the upper end of the rising portion 1A to the upper surface of the flange-shaped footing portion 1B.

Japanese Unexamined Patent Publication No. 2013-194422

By the way, the demand for energy saving in houses and the like is increasing year by year, and further improvement is required not only in the wall surface and openings of the building but also in the heat insulating performance under the floor of the building.

However, in order to improve the heat insulating property under the floor, when trying to increase (thicken) the thickness of the straight heat insulating material 2 [see FIGS. 3 (b) and 3 (d)] inside the rising portion 1A as described above. In addition to increasing the cost of a house or the like, the heat insulating material 2 may interfere with a large pull or a bundle that supports the floor material or the like in the underfloor space.

Further, as shown in FIG. 3C, the heat insulating material 2 in the horizontal direction on one side of the heat insulating material 2 having a substantially L-shaped cross section and along the surface of the soil concrete layer 3 is placed inside the soil floor D (closer to the center). ) Even if you try to extend it in the direction, as in the above, the bundle of floors etc. will interfere and some parts will not be able to arrange the heat insulating material, and this part will function as a heat escape port (heat bridge). Resulting in.

In this way, it is difficult to significantly improve the heat insulating property under the floor simply by increasing the volume (thickness, length, etc.) of the heat insulating material arranged under the floor of the building, which complicates the construction work and costs. The effect is also low. Therefore, an effective alternative method for heat insulation under the floor of a building is required.

An object of the present invention is to provide an underfloor heat insulating structure capable of improving the heat insulating property under the floor of a building with a small cost increase.

The underfloor heat insulating structure of the present invention is a foundation that supports the lower part of a building, and has a rising portion that protrudes upward from the ground and surrounds the underfloor space, and a footing portion that is arranged in the ground below the rising portion. Along the inner surface of the rising portion, the foundation including the foundation, the raised soil portion in which soil is laminated on the soil ground surrounded by the rising portion, the soil concrete layer laminated on the raised soil portion, and the inner surface of the rising portion. A basic heat insulating material arranged so as to reach the upper surface of the footing portion is provided.
A part of the soil in the raised soil part in contact with the foundation heat insulating material is removed.
A groove is formed in the edge of the soil concrete layer in contact with the foundation heat insulating material from which the soil has been removed , the end of the soil concrete layer is in contact with the foundation heat insulating material, and the end is the groove. The bottom of the groove is provided at the same height in the vertical direction as the ground outside the rising portion.

The portion where the bottom portion of the groove is at the same height in the vertical direction as the ground outside the rising portion does not have to be the entire bottom portion, and at least the end portion on the foundation heat insulating material side at the bottom portion of the groove is the said. It suffices to be at the same height as the outer ground. Therefore, the bottom of the groove includes not only a flat surface but also an inclined surface at the bottom.

Further, the underfloor heat insulating structure of the present invention is a foundation that supports the lower part of the building, and is a rising portion that protrudes upward from the ground and surrounds the underfloor space, and a footing portion that is arranged in the ground below the rising portion. On the foundation including the above, the raised soil portion where soil is laminated on the soil ground surrounded by the rising portion, the soil concrete layer laminated on the raised soil portion, and the inner surface of the rising portion. A basic heat insulating material arranged along the upper surface of the footing portion is provided.
Part of the soil in the raised soil area adjacent to the foundation insulation material was removed.
In above the footing portion of said base, and, in the position from the previous SL underlying insulation material up to the earth floor concrete layer, a second insulation made of the concrete and the raised earthen portion of material with a heat conductivity lower than the soil A material is arranged, and an inclined groove is formed at an edge portion of the inclined groove in contact with the basic heat insulating material from which the soil has been removed by the second heat insulating material, and an end portion of the inclined groove in contact with the basic heat insulating material. Is provided at the same height as the ground outside the rising portion in the vertical direction .

According to the present invention, the amount of soil soil (heat medium) near the connection between the rising portion of the foundation (cloth foundation) and the footing portion, which allows heat to easily enter and exit even in the underfloor space, is reduced, and instead, the foundation is insulated. By arranging air (space such as a groove) having a lower thermal conductivity than the soil soil or a second heat insulating material between the material and the soil concrete (layer), the lower part inside the foundation (cloth foundation). It is possible to reduce the heat that wraps around the footing portion and escapes toward the outside ground. Therefore, the underfloor heat insulating structure of the present invention can improve the heat insulating property around the foundation under the floor of the building.

(A) and (b) are cross-sectional views showing the underfloor heat insulating structure of the first embodiment of the present invention. (A)-(d) are sectional views which show the underfloor insulation structure of the 2nd Embodiment of this invention. (A) is a perspective view showing a conventional underfloor heat insulating structure, and (b) to (d) are sectional views showing a structure around a foundation.

FIG. 1 is a cross-sectional view showing an underfloor heat insulating structure according to the first embodiment of the present invention.
The illustrated building has a foundation 1 that supports the foundation and walls of the building, and a floor material (not shown) on the first floor of the building that is supported above the foundation 1. Between the foundation 1 and the floor material. A partitioned underfloor space S is formed in the building. A member (not shown) that supports the floor material, such as a bundle or a large pull, is arranged in the underfloor space S.

In the figure, the height of the ground around the building, that is, the horizontal ground upper surface that serves as the reference plane for the building, is indicated by GL, and the soil floor inside the foundation 1 (raised soil floor) formed by the earth filling. The height of the surface is displayed in DL. However, the height DL of the soil floor is not constant in the soil floor, and may differ depending on the location inside the foundation 1.

As illustrated in FIG. 3 (conventional example), the foundation 1 is a cloth foundation that extends continuously (in a cloth shape) to the outer periphery of the building, and has a footing portion 1B extending horizontally in the ground and a width of the footing portion 1B. It has an inverted T-shaped cross section with a rising portion 1A extending upward from substantially the center of the direction and projecting from the ground (GL) at a small height.

Further, the rising portion 1A of the foundation 1 is arranged so as to surround the underfloor space S, and a predetermined waste concrete layer 10 and a crushed stone layer 11 are provided below the footing portion 1B. There is.

On the upper side of the rising portion 1A, a base 20 fixed to the upper surface side thereof and an outer wall (not shown) fixed on the base 20 are arranged. Further, a soil concrete layer 3 is laid on the ground (ground, that is, the soil floor) of the underfloor space S surrounded by the rising portion 1A.

Then, in the underfloor heat insulating structure of the embodiment, the heat insulating material 2 (basic heat insulating material) is added between the soil concrete layer 3 and the rising portion 1A of the foundation 1 and on the inner surface of the rising portion 1A. ing. This heat insulating material 2 suppresses the inflow and outflow of heat between the outside (GL side on the outdoor side) and the indoor side (DL side on the underfloor space S side) through the foundation 1, and improves the heat insulating property of the underfloor space S. Can be enhanced.

Here, as shown in FIGS. 1 (a) and 1 (b), the feature of the underfloor heat insulating structure of the first embodiment is that a part of the soil in the soil portion (height DL) adjacent to the heat insulating material 2 is a part of the soil. At the edge of the soil concrete layer 3 in contact with the heat insulating material 2, the height of the upper surface of the end of the soil concrete layer 3 on the heat insulating material 2 side is lowered to the same height as the ground (height GL) outside the foundation. It is a point that a groove (recessed groove 3a, inclined groove 3b) is provided. That is, at least a part of the bottom portion (end portion on the heat insulating material 2 side) of the groove (3a, 3b) has the same height in the vertical direction as the ground (GL) outside the rising portion 1A. This is the greatest feature of this embodiment.

More specifically, the concave portion (recessed groove 3a) or the inclined surface (inclined groove 3b) of the edge portion (outer peripheral edge portion) of the soil concrete layer 3 has this portion (edge of the soil concrete layer 3) as described above. The part) is provided so as to be dug down, and the soil between the soils under these grooves is removed in advance before the construction of the grooves 3a and 3b.

Therefore, the amount of soil above the footing portion 1B of the foundation 1 and between the soil concrete layer 3 is clearly reduced as compared with the conventional example shown in FIG. 3 (d). That is, with respect to this portion, the amount of soil (heat medium) having a large thermal conductivity as compared with the heat insulating material or the like is reduced as compared with the conventional structure. Thereby, the underfloor heat insulating structure of the present embodiment can reduce the heat escaping from the lower part inside the foundation 1 (cloth foundation) around the footing portion 1B toward the outside ground.

It is known that in the soil portion inside the foundation 1, a large amount of heat flows out from the portion corresponding to the air outside the foundation (the portion above the ground height GL). Therefore, as shown in FIGS. 1 (a) and 1 (b), the height of the upper surface of the end (edge) of the concave groove 3a or the inclined groove 3b on the heat insulating material 2 side at the edge of the soil concrete layer 3. By setting the height to be the same as the height GL of the ground outside the rising portion 1A, the heat insulating effect of the underfloor space S can be further improved, and effective heat insulating can be achieved.

The cross-sectional shape of the groove for heat insulation at the edge of the soil concrete layer 3 is not limited to the concave groove 3a and the inclined groove 3b shown in the figure, and the height becomes lower toward the edge of the soil concrete layer 3. It may be in shape. For example, it may be shaped like a staircase.

Further, it is known that the region of the concrete layer 3 near the center inside the concave groove 3a or the inclined groove 3b at the edge is connected to the difficult layer (the layer whose temperature is substantially constant throughout the year) about 10 m below the ground. Therefore, the concave groove 3a and the inclined groove 3b do not need to be formed large and wide from the edge portion. Therefore, the concave groove 3a and the inclined groove 3b may be formed in the range of 50 mm to 1000 mm from the end portion (edge portion) on the heat insulating material 2 side.

Next, the second embodiment of the present invention will be described.
FIG. 2 is a cross-sectional view showing an underfloor heat insulating structure according to a second embodiment of the present invention.

Similar to the first embodiment, the second embodiment also has an underfloor space S formed between the foundation 1 that supports the foundation and walls of the building, and the foundation 1 and the floor material (not shown). .. The soil concrete layer 3 is laid on the ground (ground, that is, the soil floor) of the underfloor space S. In addition, the height of the ground around the building (the upper surface of the horizontal ground) is displayed in GL, and the height of the soil surface inside the foundation 1 formed by the earth filling is displayed in DL.

The foundation 1 is a cloth foundation, and has a footing portion 1B extending horizontally in the ground and a rising portion 1A extending upward from substantially the center of the footing portion 1B in the width direction and protruding from the ground (GL). As in the first embodiment, the base 20 fixed to the upper surface side is arranged on the upper side of the rising portion 1A, while the heat insulating material 2 (basic heat insulating material) is arranged on the inner side surface of the rising portion 1A. Is attached.

The feature of the underfloor heat insulating structure in the second embodiment is that, as shown in FIGS. 2 (a) to 2 (d), a part of the soil in the soil portion (height DL) adjacent to the heat insulating material 2 is removed, and the soil concrete. A second heat insulating material (lightweight concrete bodies 4, 4') made of concrete and a material having a lower thermal conductivity than the soil in the soil portion between the edge portion adjacent to the heat insulating material 2 in the layer 3 and the heat insulating material 2. ) Is arranged.

More specifically, the lightweight concrete body 4 shown in FIG. 2A is provided at the edge of the soil concrete layer 3 and after removing the soil between the heat insulating material 2 and along the heat insulating material 2. It is finished in a straight shape.

With this configuration, as in the first embodiment, the amount of soil (heat medium) having a large specific heat as compared with the heat insulating material or the like is reduced on the upper side of the footing portion 1B as compared with the conventional structure. Therefore, the underfloor heat insulating structure of the present embodiment can reduce the heat that wraps around the footing portion 1B from the lower part inside the foundation 1 (cloth foundation) and escapes toward the outside ground. Moreover, the underfloor heat insulating structure of this embodiment can be expected to have a synergistic effect of heat insulating by the lightweight concrete body 4.

Further, as a modification of FIG. 2A, as shown in FIG. 2B, the amount of soil in the vicinity of the lightweight concrete body 4 (on the footing portion 1B) is further reduced, and the portion is covered with the soil concrete layer 3. You may try to fill it. Thereby, the heat insulating performance around the lower part of the foundation 1 can be further improved.

Further, as shown in FIG. 2 (c), the soil concrete layer 3 portion expanded in FIG. 2 (b) may be formed by the lightweight concrete body 4'. Further, as shown in FIG. 2D, the lightweight concrete body 4'can be formed with a concave groove 3a, an inclined groove 3b, or the like described in the first embodiment at the edge thereof. In this case, as in the case of the first embodiment, it is desirable that the height of the upper surface of the end portion on the heat insulating material 2 side is lowered to the same height as the ground (height GL) outside the foundation. As a result, the heat insulating property of the underfloor space S is further improved.

In addition to the lightweight concrete, lightweight concrete blocks, bricks, ceramic siding, wood, and wood-based materials are examples of materials that can be used as the second heat insulating material and have a lower thermal conductivity than concrete and soil in the soil. Insulation material etc. can be mentioned.

Further, as the heat insulating material 2 (basic heat insulating material) attached to the inner surface of the rising portion 1A of the foundation 1, the foamed resin heat insulating material has a smaller thickness than the foamed resin heat insulating material and has higher heat insulating performance. It is desirable to use a stack of vacuum heat insulating materials.

It is desirable that the multi-layer heat insulating material 2 is arranged on the rising portion 1A side with the foamed resin-based heat insulating material side facing. Thereby, the vacuum heat insulating material does not come into direct contact with the foundation 1, and it is possible to prevent the occurrence of damage that tends to occur when the vacuum heat insulating material is attached to the rising portion 1AB.

As the foamed resin-based heat insulating material of the present embodiment, for example, a plate-like body such as polystyrene foam, urethane foam, or phenol foam, which is excellent in heat resistance and impact resistance, is adopted.

With the above configuration, the underfloor heat insulating structure of the present embodiment can effectively improve the heat insulating property around the foundation under the floor of the building without causing an excessive cost increase.

1 Foundation (cloth foundation)
1A Rising part 1B Footing part 2 Insulation material 3 Soil concrete layer 3a, 3b Grooves 4, 4'Lightweight concrete body 10 Discarded concrete layer 11 Crushed stone layer 20 Base DL Soil height GL Ground height S Underfloor space

Claims (2)

A foundation that supports the lower part of the building and includes a rising portion that protrudes upward from the ground and surrounds the underfloor space, and a footing portion that is arranged in the ground below the rising portion.
Raised soil floor area where soil is laminated on the soil floor ground surrounded by the rising portion, and
The soil concrete layer laminated on the raised soil and the soil
A basic heat insulating material arranged along the inner surface of the rising portion to reach the upper surface of the footing portion is provided.
A part of the soil in the raised soil part in contact with the foundation heat insulating material is removed.
A groove is formed in the soil concrete layer at the edge of the soil concrete layer in contact with the foundation heat insulating material from which the soil has been removed.
The end of the soil concrete layer is in contact with the foundation heat insulating material, and the end constitutes the bottom of the groove.
An underfloor heat insulating structure characterized in that the bottom portion of the groove is provided at the same height in the vertical direction as the ground outside the rising portion. A foundation that supports the lower part of the building and includes a rising portion that protrudes upward from the ground and surrounds the underfloor space, and a footing portion that is arranged in the ground below the rising portion.
Raised soil floor area where soil is laminated on the soil floor ground surrounded by the rising portion, and
The soil concrete layer laminated on the raised soil and the soil
A basic heat insulating material arranged along the inner surface of the rising portion to reach the upper surface of the footing portion is provided.
Some of the soil of the raised earthen portion is removed adjacent to said foundation insulation,
In above the footing portion of said base, and, in the position from the previous SL underlying insulation material up to the earth floor concrete layer, a second insulation made of the concrete and the raised earthen portion of material with a heat conductivity lower than the soil The material is arranged and
The second heat insulating material forms an inclined groove at the edge in contact with the basic heat insulating material from which the soil has been removed.
An underfloor heat insulating structure characterized in that an end portion of the inclined groove in contact with the basic heat insulating material is provided at the same height as the ground outside the rising portion in the vertical direction.

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