JPH11241425A - Thermal insulating material for joist of house making use of lightweight shape steel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal insulating material for joist covered with a lightweight shape steel and a foaming resin thermal insulating material. SOLUTION: In a foamed resin thermal insulating material covered with a C-shaped lightweight shape steel of a floor joist 4, the thermal insulating material is constituted of an approximately L-shaped cover member 2 and an approximately U-shaped cover member 3. The cover member 3 forms a flat side section cover section 2a on the side of a steel material in a vertical part and a lower surface section covering projection 2b in a horizontal part, the bearing cover member 3 forms a fitting projection 3a and, at the same time, a clamping projection 3b for bearing and fixing the cover member is formed in the lower surface section of the bearing cover member 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat insulating material used for floor joists of houses using lightweight section steel. More specifically, a lightweight section steel that is used as a floor joist of a house using a lightweight section steel and that has a C-shaped cross-section and that is covered with a foamed resin insulation material with good workability and does insulation without falling off The present invention relates to a heat insulating material for joists of a house using the same.

[0002]

2. Description of the Related Art Conventionally, wood is used for wooden joists of wooden house floors. Such wooden joists are difficult to conduct heat and have a certain degree of heat insulating properties. It was not considered necessary. On the other hand, in the case of floor joists in houses using lightweight section steel, the cross-sectional shape is C
Although a steel frame made of a steel material 4 such as a light-groove section steel, a lip channel steel, or the like was used, as shown in FIG. Since the material 12 was laid, it was considered that it was not always necessary to further lay a heat insulating material. Further, when it is necessary to lay a heat insulating material to improve the heat insulating property, since it is not easy to cover the frame material itself such as the joist, it is made of the steel material 4 on the lower surface side of the discarded plate 11. The heat insulating materials 10a and 10b were laid and covered only on the portions excluding the joists. However, in this case, since the steel material 4 of the floor joist is directly exposed to the outside temperature, the floor is liable to decay due to easy dew condensation, and it cannot be said that the heat insulating property is sufficient. Therefore, when it is absolutely necessary to insulate the steel material 4 itself of the floor joist in order to improve the heat insulating property, a method of winding a glass fiber mat or the like around the steel material 4 itself and affixing it with an adhesive to perform heat insulation. Attempted. However, wrapping a glass fiber mat or the like around the floor joist steel 4 itself and attaching it with an adhesive to perform heat insulation significantly increases the amount of use of the heat insulating material and causes the heat insulating material to fall off. , Because it takes time,
From the viewpoint of cost saving and the like, it has not been generally practiced to cover the steel member 4 itself of the floor joist, which is a framing material, to perform heat insulation.

[0003]

However, in recent years,
With the global warming caused by carbon dioxide gas, further energy efficiency is required for energy saving, and even the frame itself, which has not been heat-insulated at all, is covered with heat-insulating material to save energy. Is required. Therefore, glass fiber mats were wound around the framing material itself for heat insulation.However, because the framing material itself has a special cross-sectional shape, it was wrapped tightly with glass wool heat insulating material, etc. It is not easy to perform heat insulation, and it is difficult to perform heat insulation with good workability.

[0004]

Means for Solving the Problems The inventor of the present invention has conducted intensive studies in view of the above problems, and as a result, it has been found that the heat insulating material can be covered without falling off, and that the cross-sectional shape is improved in order to provide heat insulation with good workability. Is coated with at least two members, namely, a coating member 2 having a substantially L-shaped cross section and a support coating member 3 having a substantially U-shaped cross section, and a support coating member 3 having a substantially U-shaped cross section. Between the pinching projection 3b and the lower surface 4a of the steel material 4 for covering the lower surface of the substantially L-shaped coating member 2.
The present invention has been completed based on the finding that the substantially L-shaped covering member 2 can be prevented from falling off by supporting and fixing the substantially L-shaped covering member 2 with the b interposed therebetween.
That is, the heat insulating material for a joist of a house using the lightweight shaped steel of the present invention is made of a foamed resin for covering and insulating a C-shaped steel material used as a floor joist of a house using the lightweight shaped steel. In the heat insulating material, the heat insulating material made of foamed resin is composed of at least two members of a covering member having a substantially L-shaped cross section and a supporting covering member having a substantially U-shaped cross section. Forming a flat portion side coating portion covering the flat portion side of the side surface of the steel material in a vertical portion thereof, and forming a projection portion for lower surface portion covering the lower surface portion side of the steel material in the horizontal portion. The substantially U-shaped support cover member has a fitting projection formed on a side surface thereof for fitting into the groove of the steel material, and the support cover member protrudes toward the steel material on the lower surface of the support cover member. The lower surface covering projection of the substantially L-shaped covering member Substantially L by being sandwiched between the lower surface of the steel
It is characterized by forming a pinching projection for supporting and fixing the mold covering member.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [I] Insulation material made of foam resin for joist of house using lightweight section steel (1) Structure The insulation material 1 of joist of a house using lightweight section steel of the present invention is shown in FIG. As shown in FIG.
And at least two members of the supporting and covering member 3 having a substantially U-shaped cross section. Also, if the cross-sectional shape is C
If only the steel material 4 is covered and insulated, the shape of the combined heat insulating material 1 may be a simple shape having a substantially square cross section as shown in FIG. FIG.
As shown in FIG. 6, the underfloor insulation materials 10a and 10b may be formed to be supportable, or as shown in FIGS.
It can also be formed integrally with the underfloor insulation materials 10a and 10b.

(A) Covering member 2 having a substantially L-shaped cross section As shown in FIG. 1, the covering member 2 having a substantially L-shaped cross section has a flat portion-side covering portion 2a formed at a vertical portion thereof, and A projection 2b for covering the lower surface is formed at the portion.

(A) Flat portion side covering portion The flat portion side covering portion 2a formed in a vertical portion of the covering member 2 having a substantially L-shaped cross section is a cross section used as a floor joist of a house using lightweight section steel. The flat portion 4b side of the steel material 4 such as a light channel steel, a lip channel steel or the like having a C shape is covered. As shown in FIG. 2, when the underfloor heat insulating materials 10a and 10b are laid on the upper part of the flat portion side covering portion 2a adjacent to the joist heat insulating material 1 of the house using the lightweight section steel of the present invention. The step 2c may be formed so that the underfloor heat insulating materials 10a and 10b do not fall off. As shown in FIGS. 4 and 5, the stepped portion 2 c is made of a flat portion 4 b of the steel material 4 where the underfloor heat insulating materials 10 a and 10 b are formed.
It is also possible to prevent the underfloor insulation materials 10a and 10b from falling off by supporting the entire underside of the flat portion side covering portion 2a.

(B) Projecting portion for covering lower surface portion The projecting portion 2b for covering the lower surface portion formed on the horizontal portion side of the covering member 2 having a substantially L-shaped cross section protrudes toward the steel material 4 side and uses a lightweight section steel. The cross section used as a floor joist of a house is formed so as to cover the lower surface 4a side of a steel material 4 such as a C-shaped light channel steel, a lip channel steel or the like.

(B) Support coating member having a substantially U-shaped cross section The support coating member 3 having a substantially U-shaped cross section includes a fitting projection 3a projecting toward the steel material 4 as shown in FIG. And a pinching projection 3b that also projects to the steel material 4 side.

(A) Fitting Projection A fitting projection 3a that fits into the groove 4c of the steel material 4 is formed on the side surface of the supporting and covering member 3 having a substantially U-shaped cross section. The joint projection 3a is fitted into the groove 4c of the steel material 4, and is supported from below by the bottom 4a of the steel material 4, thereby preventing the support coating member 3 having a substantially U-shaped cross section from falling off. As shown in FIG. 2, a recess 5 can be formed on the steel member 4 side of the fitting projection 3a in order to reduce costs. As shown in FIG. 2, the underfloor heat insulating material 10a, which is adjacent to the joist heat insulating material 1 of the house using the lightweight section steel of the present invention, is provided on the upper part of the supporting and covering member 3 having a substantially U-shaped cross section. 1
The step portion 3c can be formed so that the underfloor heat insulating materials 10a and 10b do not fall off when the 0b is laid. As shown in FIGS. 4 and 5, the step portion 3 c is provided with an underfloor insulating material 10.
a, 10b is the depth until it comes into contact with the steel material 4, and FIG.
As shown in FIG. 5, the lower end of the fitting projection 3a can be made lower than the upper end of the fitting projection 3a, whereby the support covering member 3 as a whole can support the underfloor heat insulating materials 10a and 10b to prevent falling off.

(B) Nipping projections Nipping projections 3b projecting toward the steel material 4 are formed on the lower surface 3d side of the supporting and covering member 3 having a substantially U-shaped cross section. The cover member 2 having a substantially L-shaped cross section is sandwiched between the portion 3b and the lower surface portion 4a of the steel member with the projection 2b for covering the lower surface portion of the cover member 2 having a substantially L-shaped cross section.
To prevent the covering member 2 having a substantially L-shaped cross section from falling off. As shown in FIG. 4, the pinching projection 3 b has a bottom 2 d of the covering member 2 having a substantially L-shaped cross section.
It is also possible to support the whole and prevent the covering member 2 having a substantially L-shaped cross section from falling off. Alternatively, FIG.
And (b), as shown in FIG.
4 mm in height (depth) on the contact surface between the
Hereinafter, preferably, the fitting concave-convex portions 2e, 3e having a size of 3 to 2 mm are used.
Can be formed to prevent the covering member 2 having a substantially L-shaped cross section from easily coming off and falling off.

(2) Shape The covering member 2 having a substantially L-shaped cross section and the supporting and covering member 3 having a substantially U-shaped cross section may be solid or hollow. Alternatively, as shown in FIGS. 2, 6, and 8, the concave portion 5 may be formed. In addition, the shape is a steel material such as a light channel steel, a lip channel steel or the like having a C-shaped cross section used as a floor joist.
Is covered by combining the covering member 2 having a substantially L-shaped cross section and the supporting and covering member 3 having a substantially U-shaped cross section, and performing heat insulation, so that the size of the steel material 4 to be used has an appropriate size. Although it is possible to select and adopt one, it can also be cut into an appropriate size depending on the use situation, location, and the like.

The covering member 2 having a substantially L-shaped cross section and the supporting and covering member 3 having a substantially U-shaped cross section generally have a wall thickness of usually 20 to 20 to maintain appropriate heat insulation and moderate strength.
90 mm, preferably 20 to 50 mm, particularly preferably 20 to 40 mm is used. The length of the covering member 2 having a substantially L-shaped cross section and the length of the supporting and covering member 3 having a substantially U-shaped cross section are approximately 900 mm, and the housing using the lightweight section steel of the present invention in a state where both members are combined. Insulation material 1 for joists, length 600-2,000 mm, height 300
It is preferable that the external shape is approximately rectangular parallelepiped having a size of about 600 mm and a width of 30 to 200 mm. Also,
Insulation material 1 for joists of houses using these lightweight sections is shown in FIG.
As shown in FIG. 2, in order to cover and insulate the entirety of the steel material 4 such as a light channel steel having a C-shaped cross section and a lip channel steel, the steel 4
In order to prevent the heat insulating effect from decreasing at the joint when connecting several joist heat insulating materials 1 according to the present invention in accordance with the length, a substantially L-shaped covering member 2 and a substantially U-shaped supporting coating are provided. Member 3
May be formed at both ends.

The heat insulating material 1 for joists of houses using the lightweight section steel of the present invention is foamed and molded with a foamed resin in a mold. It is preferable from the viewpoint of cost. In addition, basically, it is preferable that the cross-sectional shape is the shape of the covering member 2 having a substantially L shape and the cross-sectional shape is the shape of the supporting and covering member 3 having a substantially U shape, but these are each divided into two or more members. It can also be formed. The shape of the covering member 2 having a substantially L-shaped cross section and the supporting covering member 3 having a substantially U-shaped cross section in the thermal insulation material 1 for a joist of a house using the lightweight shaped steel of the present invention is obtained by foaming a resin. If it is molded, if it cannot be die-cut, the cost cannot be reduced by mass production. Therefore, it is necessary to have a structure that can be die-cut like the above structure.

(3) Material (A) Foam Resin The heat-insulating material 1 for joists of houses using the lightweight section steel of the present invention is made of polyolefin resin foam, polyethylene, polypropylene or other polyolefin resin foam. Or foamed resin such as styrene-modified polyolefin-based resin foam. The foamed resin is
Specifically, for example, polystyrene resin, polyethylene, polyolefin resin such as polypropylene, or synthetic resin such as styrene-modified polyolefin resin, foamed at a foaming ratio of 25 to 80 times, usually the density Of 0.0125 to 0.04 g / cm ³ and a high closed cell rate.

[II] Floor joists for houses using lightweight section steel Insulation material made of foamed resin for joists of houses using lightweight section steel 1
As a floor joist of a house using a light-weight section steel covered by the above, a steel material 4 such as a light channel section steel having a C-shaped cross section and a lip channel section steel is used. The steel material 4 having a C-shaped cross section, such as a light channel steel or a lip channel steel, is used for a so-called lightweight steel frame prefabricated house or steel house, and specifically, as shown in FIG. In the lip channel steel, the height (H) is 300 mm, the width (W) is 50 mm, the length of the lip is 20 mm, the thickness (t) is 1.6 mm, or the height (H) is 235 mm and the width ( W) is 40 mm, lip length is 20 mm, thickness (t) is 1.6 mm, or height (H) is 184 mm, width (W) is 40 mm, lip length is 20 mm, and thickness (t) is 1.0 mm or the like, or in a light channel steel, the height (H) is 304
mm, width (W) is 40 mm, thickness (t) is 1.6 mm,
Or, the height (H) is 238 mm, the width (W) is 40 mm,
Thickness (t) is 1.2 mm or height (H) is 92 m
m, the width (W) is 40 mm, and the thickness (t) is 1.2 mm.

[III] Construction In order to cover and insulate a steel material 4 having a C-shaped cross section as a joist of a house using the above lightweight section steel, as shown in FIG.
First, the fitting projection 3b formed on the side surface of the substantially U-shaped supporting and covering member 3 is fitted into the groove 4c of the C-shaped steel material 4 to cover the steel material 4 on the groove 4c side. Next, the coating member 2 having a substantially L-shaped cross section is brought into contact with the flat portion side 4b of the side surface of the steel material 4, and the lower surface coating projection 2b formed below the lower surface portion 4b is formed in cross section with the lower surface portion 4a of the steel material 4. The lower surface portion 4a of the steel material 4 is fitted between the support coating member 3 having a substantially
While covering the side, it is sandwiched between the supporting and covering member 3 having a substantially U-shaped cross section and the lower surface 4a of the steel material 4 to support and fix the covering member 2 having a substantially L-shaped cross section. Then, underfloor insulation materials 10a and 10b are laid adjacent to the joist insulation material 1 of the house using the lightweight section steel, and further, the C-shaped steel material 4 and the joist insulation material 1 of the house using the lightweight section steel are used. After laying the discarding plate 11 on the scraping plate 11, the finishing material 12
Laying.

[0018]

The heat insulating material for joists of houses using the lightweight section steel according to the present invention comprises at least two members: a covering member 2 having a substantially L-shaped cross section and a supporting covering member 3 having a substantially U-shaped cross section. A flat portion 4b of a steel material 4 such as a light-groove section steel or a lip channel section steel having a C-shaped cross-section and a flat-portion-side coating portion 2a formed on a vertical portion of the covering member 2 having a substantially L-shaped cross-section. The lower surface 4a of the steel material 4 is covered with the lower surface coating projection 2b formed on the horizontal portion. Further, the groove-side covering portion 3a formed on the side surface of the support coating member 3 having a substantially U-shaped cross-section is fitted into the groove 4c of the steel material 4 having a C-shaped cross-section, and the cross-sectional shape is substantially U-shaped. The supporting and covering member 3 is prevented from falling off, and the cross-sectional shape is substantially L between the sandwiching projection 3b formed on the lower surface 3d and the lower surface 4a of the steel material 4 with the lower surface coating projection 2b interposed therebetween. The mold covering member 2 is supported and fixed to be integrated.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A foamed resin insulation material for joists of a house using the lightweight section steel of the present invention will be described below with reference to one embodiment.
This will be specifically described with reference to the drawings. FIG. 1 shows that the sectional shape is C
FIG. 2 is a perspective view of a foamed resin heat insulating material for a joist of a house using the lightweight section steel of the present invention covered and insulated on a mold steel material.
FIG. 3 is a cross-sectional view of a foamed resin insulation material for a joist of a house using the lightweight section steel of the present invention, in which a cross-sectional shape is coated with a C-shaped steel material, and further, an underfloor insulation material, a discarded plate, and a finishing material are applied. ,
3 to 5 are cross-sectional views of another embodiment of a foamed resin heat insulating material for joists of houses using the lightweight section steel of the present invention, and FIG. 6 is a light weight of the present invention formed integrally with an underfloor heat insulating material. It is sectional drawing of the floor structure using the insulation material made of the foam resin for the joist of the house which uses a shape steel. FIGS. 7-8 are the covering member which cross-sectional shape used for the floor structure of FIG. 9 shows the dimensions (unit: mm) of a heat insulating material formed integrally with the material and the supporting and covering member having a substantially U-shaped cross section. FIG. The cross-sectional shape obtained by separating the underfloor heat insulating material from the heat insulating material integrally formed represents the dimension (unit: mm) of the substantially L-shaped covering member. FIG. 10 shows the lower surface covering projection and the fitting projection. 2 shows a partially enlarged view of a contact surface.

1 has a length of 909 mm shown in FIG.
Foaming magnification 50 times of dimensions of width 285mm, thickness 90mm,
Support coating member 3 made of expanded polystyrene having a density of 0.02 g / cm ³ and a closed cell ratio of about 100%, and having a substantially U-shaped cross section
, Length 909 mm, width 285 mm, shown in FIG.
Foaming ratio of 50 times with a thickness of 90 mm, density 0.02 g
/ Cm ³ , a foamed resin insulation material for a joist of a house using a lightweight section steel made of a foamed polystyrene having a closed cell ratio of about 100% and a covering member 2 having a substantially L-shaped cross section. is there. Height (H) is 235mm, width (W) is 4
0 mm, lip length 20 mm, thickness (t) 1.6
8 and a length (L) of 3,600 mm were formed in the groove 4c of the C-shaped lip channel steel 4 and in the side surface portion of the support coating member 3 whose cross-sectional shape shown in FIG. By fitting the fitting projections 3b, four support coating members 3 having a substantially U-shaped cross section were connected to and fixed to the steel material 4 in the longitudinal direction of the steel material 4. Next, the flat portion 4b on the side surface of the steel material 4
The lower surface covering projection 2b formed on the horizontal portion of the covering member 2 after contacting and covering the flat portion side covering portion 2a formed on the vertical portion of the covering member 2 having the substantially L-shaped cross section.
In order to cover the lower surface 4a side of the steel material 4,
Lower surface portion 4a and the supporting and covering member 3 having a substantially U-shaped cross section.
The lower surface 4a of the steel material 4 and the cross-sectional shape are formed on the lower surface side of the substantially U-shaped supporting and covering member 3 by being inserted into the concave portion between the pinching projections 3b formed on the lower surface side of the steel member 4. The lower surface portion coating projections 2b were connected and fixed in the length direction of the steel material 4 by being sandwiched and fixed between the clamping projections 3b.

The under-floor insulating materials 10a, 10b having a thickness of 50 mm are provided on the step 2a of the covering member 2 having a substantially L-shaped cross section and the step 3a of the supporting covering member 3 having a substantially U-shaped cross section.
Is further laid, and a 12 mm-thick discard plate 11 is laid on the joist heat insulating material 1 of a house using a C-shaped steel material 4 and a lightweight section steel. The finishing material 12 is laid. The heat insulating material 1 for a joist of a house using the lightweight section steel of the present invention formed in this manner has extremely good workability at the time of construction, is easy to perform, can perform heat insulation at a low cost, and furthermore, has floors. Since the cross-sectional shape used as a joist can be covered without falling off from the C-shaped steel material 4, and furthermore, the heat retention is sufficient and there is no dew condensation.
The floor was hard to rot.

[0022]

The heat insulating material for joists of a house using the lightweight section steel of the present invention configured as described above is used as a floor joist to cover and insulate a C-shaped steel material without falling off. In addition, since the workability is extremely good, heat insulation can be performed at low cost.

[Brief description of the drawings]

FIG. 1 is a perspective view of a heat insulating material made of foam resin for a joist of a house using a lightweight section steel according to an embodiment of the present invention, which is covered with a lip channel steel having a C-shaped cross section and insulated.

FIG. 2 is a foamed resin for a joist of a house using the lightweight section steel of the present invention, which is coated with a lip channel steel section having a C-shaped cross-section and further provided with an underfloor insulation material, a waste board and a finishing material. It is sectional drawing of the floor structure using the heat insulating material.

[FIG. 3] FIG. 3 is a house using a lightweight section steel according to another embodiment of the present invention, in which a lip channel steel section having a C-shaped cross section is covered, and further, an underfloor insulation material, a waste plate and a finishing material are applied. It is sectional drawing of the floor structure using the insulation material made of foam resin for joist.

[FIG. 4] FIG. 4 is a house using a lightweight section steel according to another embodiment of the present invention, in which a lip channel steel section having a C-shaped cross section is coated, and further, underfloor insulation, a discarded plate, and a finishing material are applied. It is sectional drawing of the floor structure using the insulation material made of foam resin for joist.

FIG. 5 is a house using a lightweight section steel according to another embodiment of the present invention, in which a lip channel steel section having a C-shaped cross section is covered, and further, an underfloor heat insulating material, a waste plate and a finishing material are applied. It is sectional drawing of the floor structure using the insulation material made of foam resin for joist.

FIG. 6 is a floor according to an embodiment of the present invention using a foamed resin insulation material for a joist of a house using a lightweight section steel in which a covering member having a substantially L-shaped cross section is formed integrally with an underfloor insulation material. It is a partially cutaway sectional view of a structure.

FIG. 7 is a cross sectional view of the floor structure of FIG.
A front view (a), a plan view (b), and a side view (c) of a heat insulating material in which a mold covering member and an underfloor heat insulating material are integrally formed,
The numbers represent the dimensions (unit: mm).

FIG. 8 shows a front view (a), a bottom view (b), and a side view (c) of a supporting and covering member 3 having a substantially U-shaped cross section used in the floor structure of FIG. The dimensions (unit: mm) are shown.

9 is a covering member having a substantially L-shaped cross-section obtained by separating the underfloor heat-insulating material portion from the heat-insulating material in which the covering member having a substantially L-shaped cross-section and the under-floor heat-insulating material shown in FIG. 7 are integrally formed; The front view (a), the plan view (b), and the side view (c) of FIG. 1 are shown, and the numbers represent their dimensions (unit: mm).

FIG. 10 is a view showing a fitting of a projection for covering a lower surface portion of a foamed resin insulation material for a joist of a house using a lightweight section steel insulated by covering a lip channel steel having a C-shaped cross section in FIG. 1; It is the elements on larger scale of the contact surface of a joint projection part.

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1 Insulation material for joists of houses using lightweight shaped steel 2 Covering member having a substantially L-shaped cross section 2a Flat portion side covering portion 2b Projection portion for covering lower surface portion 2c Step portion 2d Bottom portion 2e Fitting convex portion 3 Cross sectional shape is substantially U-shaped supporting and covering member 3a Fitting projection 3b Nipping projection 3c Step 3d Lower surface 3e Fitting concave portion 4 Steel material having a C-shaped cross section 4a Lower surface portion of steel material 4b Flat portion of steel material 4c Groove portion of steel material 5 concave portion 10a, 10b Thermal insulation for floor 11 Discarded plate 12 Finishing material

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Seisuke Hashimoto 2-5-2, Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Chemical Corporation

Claims (4)

[Claims] 1. A foamed resin insulation material used as a floor joist of a house using lightweight shaped steel for covering a C-shaped steel material for heat insulation, wherein the foamed resin insulation material is used. A cover member having a substantially L-shaped cross-section and a supporting cover member having a substantially U-shaped cross-section, and the substantially L-shaped cover member has a side surface of the steel material at a vertical portion thereof. A flat portion side coating portion for coating the flat portion side of the steel material, and a lower surface portion projecting portion for coating the lower surface portion side of the steel material is formed on the horizontal portion thereof. Formed on the side surface thereof a fitting projection for fitting into the groove of the steel material, and projecting toward the steel material on the lower surface of the supporting and covering member to project on the lower surface of the substantially L-shaped covering member. Between the lower surface of the steel material and a substantially L-shaped covering member Characterized in that it is obtained by forming a narrow wear projections for supporting and fixing, joist insulation for residential use of lightweight shape steel. 2. The supporting member according to claim 1, wherein a stepped portion is formed on an upper surface of the covering member having a substantially L-shaped cross section and a supporting member having a substantially U-shaped cross section at a corner opposite to the steel material. Insulation material for joists of houses using lightweight section steel. 3. The heat insulating material for joists of houses using lightweight section steel according to claim 1 or 2, wherein a recess is formed in the fitting projection fitted on the groove side of the steel material. 4. A heat insulation for joists of a house using the lightweight section steel according to any one of claims 1 to 3, wherein a fitting concave-convex portion is formed on a contact surface between the lower surface portion covering projection and the fitting projection. Wood.