Fireproof subfloor structure

Abstract

To provide a fireproof subfloor structure that is easy to install and can effectively prevent fire heating from spreading from below through the joints to an upper floor during a fire.SOLUTION: In a fireproof subfloor structure 10 that is composed of multiple wooden fireproof units 20 having a rectangular flat shape, which are installed in series by supporting them on a wooden beam frame 51, the wooden fireproof units 20 are composed of a unit main body 21 and a fireproof covering material 22 attached as a single unit to cover the lower surface of the unit main body. On the peripheral end surfaces 22a of the fireproof covering materials 22 facing each other at a joint 11 of each pair of adjacent wooden fire-resistant units 20, a fireproof material storage concave groove 24 is formed in the middle part in the thickness direction extending in the direction of the extension of the joint 11. A fireproof material 25, which is a heat-activated foaming fireproof material and / or a heat-expanding fireproof material, is housed in the fireproof material storage concave groove 24 without protruding from the peripheral end surface 22a. In an event of a fire, the fireproof materials 25 foam and / or expand to fill the gap 11a in the joint 11.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a fire-resistant floor base structure constructed by supporting a plurality of wooden fire-resistant units, each having a rectangular planar shape, in series with one another on a floor beam or foundation, and to a wooden fire-resistant unit used in the fire-resistant floor base structure. [Background technology]

[0002] Buildings are required to have fire resistance so that their structural framework can be maintained even when exposed to heat from a fire, and various standards for semi-fireproof and fireproof structures are prescribed in the Building Standards Act and other laws.

[0003] For example, when constructing floors in buildings using wood, a preferred fire-resistant wooden floor is one that has a wooden floor component made of CLT (cross-laminated timber) or LVL (laminated veneer lumber) topped with a fire-resistant covering made of a surface material such as gypsum board or wet material such as concrete. However, these fire-resistant covering materials require fastening and curing, making their installation time-consuming.

[0004] On the other hand, as a fireproof floor base structure in which a floor finishing material is laid on the upper surface, a base structure for a wooden floor having a semi-fireproof structure, preferably a fireproof structure, is known in which a plurality of fireproof wooden floor units having a rectangular planar shape are arranged vertically and horizontally and supported by beam frames arranged vertically and horizontally so as to connect each pair of adjacent column frames, thereby forming a base structure for a wooden floor having a semi-fireproof structure, preferably a fireproof structure (for example, see Patent Document 1, Figure 1). With such a fireproof floor base structure, it is possible to efficiently form a base structure for a wooden floor by simply arranging and fixing a plurality of fireproof wooden floor units manufactured in advance in a factory or the like vertically and horizontally at the construction site.

[0005] Furthermore, in the case of a fire-resistant floor base structure using such fire-resistant wooden floor units, it is believed that by attaching a non-combustible layer made of gypsum panels or calcium silicate panels to the underside of the fire-resistant wooden floor unit as a fire-resistant covering material (see, for example, Patent Document 2), it is possible to effectively exhibit fire resistance, especially against fire heating from below. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2023-016386 A [Patent Document 2] Patent Publication No. 2022-021793 Summary of the Invention [Problem to be solved by the invention]

[0007] In a fire-resistant floor base structure formed by installing multiple fire-resistant wooden floor units manufactured in advance in a factory or the like in a vertical and horizontal arrangement, small gaps, for example of about 1 to 12 mm, may be left in the joints between each pair of adjacent fire-resistant wooden floor units.It is believed that fire heat from below will spread into and over the floor through the gaps in the joints, adversely affecting the fire-resistant performance, so it is necessary to effectively prevent fire heat from below from spreading into and over the floor through the gaps in the joints in the event of a fire, without compromising the ease of installation using the fire-resistant wooden floor units.

[0008] The present invention aims to provide a fire-resistant floor base structure that can effectively prevent fire heat from below from spreading into and onto the floor through gaps in the joints in the event of a fire, without compromising the ease of installation using fire-resistant wooden floor units, and a wooden fire-resistant unit for use in said fire-resistant floor base structure. [Means for solving the problem]

[0009] The present invention provides a fireproof floor base structure constructed by supporting a plurality of wooden fireproof units, each having a rectangular planar shape, on floor beams or a foundation and arranged in a row, the wooden fireproof units including a unit body made of a wooden material and a fireproof covering material having a rectangular planar shape similar to that of the unit body, which is attached integrally to cover the underside of the unit body, and at least one of the peripheral end faces of the fireproof covering material facing each other at the joints of each pair of adjacently installed wooden fireproof units has a fireproof material accommodation groove formed in an upper part of the peripheral end face, excluding the lower edge part in the thickness direction, extending in the extension direction of the joints, in which a heat-foamable fireproof material and / or a heat-expandable fireproof material is accommodated as a fireproof material, the fireproof material being accommodated in the fireproof material accommodation groove without protruding from the peripheral end face, and in the event of a fire, the fireproof material expands and / or foams to fill the gaps in the joints. This achieves the above-mentioned object by providing a fireproof floor base structure.

[0010] Furthermore, it is preferable that the fire-resistant floor base structure of the present invention is formed by stacking unit fire-resistant coating materials in a plurality of layers, and that at the peripheral end surface, the end faces of one or more layers of unit fire-resistant coating materials excluding the outermost layer are stacked with a setback from the end face of the unit fire-resistant coating material of the outermost layer, so that the setback portion provides a fire-resistant material accommodating groove.

[0011] In addition, in the fireproof floor base structure of the present invention, it is preferable that the fireproof material is a fireproof tape, a fireproof caulking material, or a fireproof paint.

[0012] Furthermore, in the fireproof floor base structure of the present invention, it is preferable that the fireproof covering material is formed using a gypsum board or a calcium silicate board.

[0013] The present invention also provides a wooden fireresistant unit for use in the above-mentioned fireresistant floor base structure, which comprises a unit body made of a wooden material having a rectangular planar shape, and a fireresistant covering material having the same rectangular planar shape as the unit body, which is attached as one piece and covers the underside of the unit body, and a fireresistant material accommodating groove is formed extending circumferentially on the peripheral end surface of the fireresistant covering material on at least one side of the rectangular planar shape, in an upper portion thereof excluding the lower edge portion in the thickness direction, and the fireresistant material accommodating groove accommodates a heat-foamable fireresistant material and / or a heat-expandable fireresistant material as the fireresistant material without protruding from the peripheral end surface, thereby achieving the above-mentioned object.

[0014] Furthermore, in the wooden fire-resistant unit of the present invention, it is preferable that the fire-resistant covering material is formed by stacking unit covering materials in a plurality of layers, and that at the peripheral end surface, the end faces of the unit covering materials of one or more layers excluding the outermost layer are stacked with a setback from the end face of the unit covering material of the outermost layer, so that the setback portion provides a fire-resistant material accommodating groove.

[0015] In the wooden fire-resistant unit of the present invention, the fire-resistant material is preferably a fire-resistant tape, a fire-resistant caulking material, or a fire-resistant paint.

[0016] Furthermore, in the wooden fire-resistant unit of the present invention, the fire-resistant covering material is preferably formed using a gypsum board or a calcium silicate board. Effect of the Invention

[0017] According to the fire-resistant floor base structure of the present invention, or the wooden fire-resistant unit used in the fire-resistant floor base structure, in the event of a fire, it is possible to effectively prevent fire heat from below from spreading into and onto the floor through the gaps in the joints, without compromising the ease of construction of the fire-resistant wooden floor unit. [Brief description of the drawings]

[0018] [Figure 1]FIG. 1 is a schematic perspective view illustrating a situation in which a fireproof floor base structure according to a preferred embodiment of the present invention is formed by supporting a plurality of fireproof wooden floor units on a beam frame and laying them horizontally and vertically. [Diagram 2] FIG. 2 is a perspective view illustrating a fire-resistant wooden floor unit forming a fire-resistant floor substructure according to a preferred embodiment of the present invention. [Diagram 3] FIG. 3(a) is a cross-sectional view of a key portion taken along line AA in FIG. 1, explaining a fire-resistant floor base structure according to a preferred embodiment of the present invention, and FIG. 3(b) is an enlarged view of part B in FIG. 3(a). [Figure 4] 4(a) to 4(f) are cross-sectional views of essential parts illustrating other forms of the fireproof material-receiving groove and the fireproof material received therein. [Diagram 5] FIG. 5 is a schematic perspective view illustrating a situation in which a fire-resistant floor base structure according to another embodiment is formed by supporting a plurality of fire-resistant wooden floor units on a beam frame and laying them vertically and horizontally. [Figure 6] FIG. 6 is a cross-sectional view of the essential parts taken along line CC in FIG. 5 with the floor finishing material laid. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] A fireproof floor base structure 10 according to a preferred embodiment of the present invention (see Figs. 3(a) and (b)) is formed by supporting a plurality of fireproof wooden floor units 20, for example, having the configuration shown in Fig. 2, vertically and horizontally arranged on beam frames 51 that are vertically and horizontally installed so as to connect each pair of adjacent column frames 50 as shown in Fig. 1, to form a base structure for a wooden floor having a quasi-fireproof structure, preferably a fireproof structure. The fireproof floor base structure 10 of this embodiment uses wooden fireproof units 20 having a rectangular planar shape that are precisely manufactured in advance in a factory or the like, making it easy to construct at the construction site and easy to form, and also has a function of effectively preventing fire heat from spreading from below through the gaps 11a of the joints 11 to the inside and above the floor in the event of a fire.

[0020] The fire-resistant floor base structure 10 of this embodiment is a fire-resistant floor base structure constructed by supporting a plurality of wooden fire-resistant units 20, each having a rectangular planar shape, in series and installed on wooden floor beams or foundations (beam frames 51 in this embodiment) as shown in Figure 1. As shown in Figure 2, the wooden fire-resistant unit 20 includes a unit body 21 made of wooden material, and a fire-resistant covering material 22, which covers the underside of the unit body 21 and is attached as a single unit, and has the same rectangular planar shape as the unit body 21. At least one of the peripheral end faces 22a of the fire-resistant covering material 22 facing each other at the joint portion 11 of each pair of adjacently installed wooden fire-resistant units 20 has a fire-resistant material accommodation groove 24 in which a heat-foamable fire-resistant material and / or a heat-expandable fire-resistant material is accommodated as the fire-resistant material 25, formed in the upper part of the peripheral end face 22a except for the lower end edge portion in the thickness direction, extending in the extension direction of the joint portion 11 as shown in Figures 3(a) and (b), and the fire-resistant material 25 is accommodated in the fire-resistant material accommodation groove 24 without protruding from the peripheral end face 22a of the fire-resistant covering material 22. In the event of a fire, the fire-resistant material 25 foams and / or expands to fill the gap 11a of the joint portion 11. Furthermore, since the load-bearing capacity of the fire-resistant covering material 22 is not large, in this embodiment, the fire-resistant covering material 22 is preferably cut out and removed at the peripheral portion of the underside of the wooden fire-resistant unit 20, which is to be placed on the beam frame 51, so that the peripheral portion of the unit body 21 can be placed on the beam frame 51.

[0021] In addition, in this embodiment, the fire-resistant coating material 22 is preferably formed by stacking unit fire-resistant coating materials 23a, 23b, and 23c in multiple layers (three layers in this embodiment), and at the peripheral end surface 22a of the fire-resistant coating material 22, the end faces of one or more layers of unit fire-resistant coating materials (in this embodiment, the second layer of unit fire-resistant coating material) 23b, excluding the outermost layer of unit fire-resistant coating material 23a, are stacked so as to be set back from the end face of the outermost layer of unit fire-resistant coating material 23a, so that a fire-resistant material accommodating groove 24 is provided by the setback portion (end face of the second layer).

[0022] In this embodiment, the fire-resistant wooden floor unit 20 that forms the fire-resistant floor base structure 10 is composed of a unit body 21 made of wooden material having a rectangular planar shape, as described above, and a fire-resistant covering material 22 having the same rectangular planar shape as the unit body 21, which covers the underside of the unit body 21 and is attached as an integral part.

[0023] The unit body 21 is preferably made of CLT (cross-laminated timber) or LVL (laminated veneer lumber) and has a rectangular planar shape, preferably about 30 to 1200 cm in length and width, so that it can be installed with its peripheral edge supported by, for example, a beam frame 51 (see FIG. 1). The unit body 21 is a wooden member with a thickness of about 2 to 50 cm. A fire-resistant covering material 22, preferably made of three layers of unit fire-resistant covering materials 23a, 23b, and 23c, is attached to the underside of the unit body 21 by being joined integrally with the unit body 21.

[0024] In this embodiment, the fireproof covering material 22 attached to the underside of the unit body 21 is formed as unit fireproof covering materials 23a, 23b, and 23c, which are formed by stacking and joining together three or more layers (three layers in this embodiment) of gypsum boards or calcium silicate boards having a rectangular planar shape of the same size as the unit body 21 and a thickness of preferably about 5 to 90 mm. In this embodiment, the unit fireproof covering materials 23a, 23b, and 23c are laminated in a state where the peripheral end surface of the unit fireproof covering material 23b of the second layer from the bottom surface is set back preferably by about 1 to 10 mm from the peripheral end surfaces of the unit fireproof covering material 23a of the first layer, which is the outermost layer, and the unit fireproof covering material 23c of the third layer, which is the innermost layer, on at least one side of the peripheral end surface 22a of the fireproof covering material 22, which will face each other at the joint portion 11 when the unit fireproof covering materials 23a, 23b, and 23c of the wooden fireproof unit 20 having a rectangular planar shape are installed in a row vertically and horizontally on the beam frame 51. As a result, a fireproof material receiving groove 24 having a rectangular cross-sectional shape and a depth of, for example, about 1 to 10 mm is formed in the upper part of the peripheral end surface 22a of the fireproof covering material 22 at least on one side of the rectangular planar shape, except for the lower edge portion of the first layer (outermost layer) unit fireproof covering material 23a at the lower end in the thickness direction. As described above, the fireproof material receiving groove 24 is adapted to receive a heat-foamable fireproof material and / or a heat-expandable fireproof material as the fireproof material 25 without protruding from the peripheral end surface 22a of the fireproof covering material 22. The fireproof covering material may be formed of two layers of unit fireproof covering material, or four or five or more layers of unit fireproof covering material, as described later.

[0025] In this embodiment, the fireproof material 25 accommodated in the fireproof material accommodation groove 24 may be any of various fireproof materials 25 known as heat-foamable fireproof materials or heat-expandable fireproof materials, which have physical properties capable of foaming and / or expanding in the event of a fire to fill the gap 11a (see Figs. 3(a) and (b)) of the joint portion 11. More specifically, the fireproof material 25 may preferably be a thin heat-expandable fireproof coating material, a heat-expandable fireproof material, a foamable fireproof coating material, a one-component modified silicone-based sealant, a one-component silylated acrylate-based sealant, a heat-expandable sealant, a modified silicone one-component sealant, or the like.

[0026] Furthermore, these fireproof materials 25, which are made of fireproof tape, fireproof caulking material, or fireproof paint, can be accommodated in the fireproof material accommodation groove 24 of the fireproof covering material 22 without protruding from the peripheral end surface 22a of the fireproof covering material 22. This makes it possible to smoothly load and lay the fireproof wooden floor units 20 vertically and horizontally while avoiding damage to the fireproof materials 25 due to contact with other objects during transportation or installation of the fireproof wooden floor units 20 on the beam frame 51, and makes it possible to more efficiently and smoothly construct the fireproof floor base structure 10 using a plurality of fireproof wooden floor units 20.

[0027] In this embodiment, the fireproof wooden floor units 20 having the above-mentioned configuration are lifted at the construction site and supported by the beam frames 51 installed vertically and horizontally as shown in Fig. 1. The lifted fireproof wooden floor units 20 are then arranged vertically and horizontally, preferably without gaps, and are then installed in a row at a predetermined position, whereby the fireproof floor base structure 10 of this embodiment can be simply and easily formed. In addition, on the upper surface of the connected unit bodies 21 of the formed fireproof floor base structure 10, various known floor finishing materials such as carpet and flooring are laid, and a floor-mounted fireproof covering material is laid between the floor finishing material and the unit bodies 21 (not shown), so that a wooden floor with improved fire resistance is efficiently formed by the fireproof floor base structure 10 of this embodiment.

[0028] Furthermore, according to the fire-resistant floor base structure 10 and fire-resistant wooden floor unit 20 of the wooden floor of this embodiment having the above-mentioned configuration, in the event of a fire, it is possible to effectively prevent fire heat from below from spreading into and onto the floor through the gaps 11a of the joint portions 11, without compromising the ease of construction using the fire-resistant wooden floor unit 20.

[0029] That is, according to this embodiment, each of the multiple fireproof wooden floor units 20 constituting the fireproof floor base structure 10 can be manufactured with high precision in advance in a factory or the like, and at the construction site, each fireproof wooden floor unit 20 can be lifted and installed vertically and horizontally, so that the fireproof floor base structure 10 can be simply and easily formed. In addition, at this time, the fireproof material 25 accommodated in the fireproof material accommodation groove 24 is accommodated without protruding from the peripheral end surface 22a of the fireproof covering material 22, so that it is possible to effectively avoid damage due to contact with other objects, which would impair the ease of construction. In addition, in the event of a fire, the fireproof material 25 made of a heat-foamable fireproof material or a heat-expandable fireproof material will foam and / or expand, thereby filling and firmly sealing the gaps 11a of the joints 11. This prevents the heat from below from spreading into and over the floor through the gaps 11a of the joints 11, making it possible to effectively suppress the spread of fire in the event of a fire.

[0030] 4(a) to (f) show other examples of the fireproof material receiving groove 24 and the fireproof material 25 received therein, which are provided on at least one of the peripheral end faces 22a of the fireproof covering material 22 that face each other at the joint portion 11 of each pair of installed wooden fireproof units 20 in the above-mentioned fireproof floor base structure 10. As shown in FIG. 4(a) to (f), the fireproof material receiving groove 24 can be provided on the end face of the second layer unit fireproof covering material 23b in the fireproof covering material 22 formed by two layers of unit fireproof covering materials 23a and 23b, for example, to receive the fireproof material 25 (see FIG. 4(a)). The fireproof material receiving groove 24 can also be provided on only one of the peripheral end faces 22a of the fireproof covering materials 22 that face each other at the joint portion 11, for example, to receive the fireproof material 25 (see FIG. 4(b)). The fire-resistant material accommodating groove 24 can also be provided across the end faces of the second and third layers of unit fire-resistant covering materials 23b, 23c in the fire-resistant covering material 22 formed, for example, by unit fire-resistant covering materials 23a, 23b, 23c, to accommodate the fire-resistant material 25 (see Figure 4(c)).

[0031] Also, the fireproof material 25 can be attached, for example, in the fireproof material receiving groove 24 by being stuck to the upper side (see FIG. 4(d)) or the lower side (see FIG. 4(e)). The fireproof covering material 22 can be formed, for example, of a single layer of covering material instead of being formed by stacking a plurality of layers of unit fireproof covering materials, and in this case, the fireproof material receiving groove 24 can be formed, for example, by cutting out the peripheral end surface 22a of the middle part in the thickness direction of the fireproof covering material 22 in a U-shape to receive the fireproof material 25 (see FIG. 4(f)).

[0032] 5 and 6 are diagrams illustrating a fireproof floor base structure 10' according to another embodiment of the present invention. In the fireproof floor base structure 10' according to this other embodiment, the fireproof wooden floor units 20' are supported by a beam frame 51 and installed in a row in a row. The unit body 21' constituting the fireproof wooden floor units 20' has a rectangular frame-like planar shape preferably about 30 to 1200 cm in length and width, and is made of a wooden material having a height of about 2 to 50 cm. On the lower surface of the rectangular frame-like unit body 21', a fireproof covering material 22, preferably made of three layers of unit fireproof covering materials 23a, 23b, and 23c, is attached by being integrally joined to the rectangular frame-like unit body 21', as in the fireproof wooden floor unit 20 of the above embodiment. In addition, at least on one side of the peripheral end surface 22a of the fire-resistant covering material 22, the peripheral end surface of the second layer of unit fire-resistant covering material 23b from the bottom surface is set back from the peripheral end surfaces of the first layer of unit fire-resistant covering material 23a, which is the outermost layer, and the third layer of unit fire-resistant covering material 23c, which is the innermost layer, and the three layers of unit fire-resistant covering materials 23a, 23b, and 23c are laminated, so that a fire-resistant material-containing groove 24 is formed in the upper part of the peripheral end surface 22a of the fire-resistant covering material 22, excluding the lower edge portion, and extends in the circumferential direction. In this fire-resistant material-containing groove 24, a heat-foamable fire-resistant material and / or a heat-expandable fire-resistant material is contained as the fire-resistant material 25 without protruding from the peripheral end surface 22a of the fire-resistant covering material 22.

[0033] In another embodiment of the fireproof floor base structure 10', similarly to the above-mentioned fireproof floor base structure 10, the fireproof wooden floor units 20' are lifted at the construction site and supported by the beam frames 51 installed vertically and horizontally, and the lifted fireproof wooden floor units 20' are arranged vertically and horizontally and installed in a row at a predetermined position, so that the fireproof floor base structure 10' can be simply and easily formed. At the same time, a wooden floor can be efficiently formed by laying various known floor finishing materials 12 such as flooring so as to cover the upper surfaces of the unit bodies 21' arranged in a row. In the fireproof floor base structure 10' of another embodiment, as shown in FIG. 6, a fireproof covering material 13 for the floor can be disposed between the unit bodies 21' and the floor finishing material 12. The fireproof covering material 13 for the floor can be attached in advance at a factory or the like so as to cover the open upper surface of the fireproof wooden floor unit 20', and the joints can be disposed in the same positions as the joints 11 of the fireproof wooden floor unit 20'.

[0034] Also, in the fireproof floor base structure 10' and the fireproof wooden floor unit 20' of this other embodiment, the three layers of unit fireproof covering materials 23a, 23b, and 23c are laminated in a state in which the peripheral end face of the unit fireproof covering material 23b of the second layer from the bottom surface is set back preferably by about 1 to 10 mm from the peripheral end faces of the unit fireproof covering material 23a of the first layer, which is the outermost layer, and the unit fireproof covering material 23c of the third layer, which is the innermost layer, on at least one side of the peripheral end face 22a of the fireproof covering material 22, which faces each other at the joint portion 11. As a result, a fireproof-material-accommodating groove 24 having a rectangular cross-sectional shape and a depth of about 1 to 10 mm, for example, is formed in the peripheral end face 22a of the fireproof covering material 22 on at least one side of the rectangular planar shape, excluding the lower edge portion of the unit fireproof covering material 23a of the first layer at the lower end in the thickness direction, and extending in the circumferential direction. As described above, this fire-resistant material accommodating groove 24 is designed to accommodate a heat-foamable fire-resistant material and / or a heat-expandable fire-resistant material as the fire-resistant material 25 without protruding from the peripheral end surface 22a of the fire-resistant covering material 22.

[0035] As a result, like the fireproof floor base structure 10 and the fireproof wooden floor unit 20 of the above-mentioned embodiment, it is possible to effectively prevent the fire heat from below from spreading into and onto the floor through the gap 11a of the joint portion 11, without impairing the ease of construction of the fireproof wooden floor unit 20' in the event of a fire. In the fireproof floor base structure 10' of this other embodiment, other forms of the fireproof material accommodation groove 24 and the fireproof material 25 accommodated therein can be adopted, for example, as shown in Figures 4(a) to (f).

[0036] The present invention is not limited to the above-mentioned embodiments, and various modifications are possible. For example, each wooden fireproof unit constituting the fireproof floor base structure can be formed by joining the lower surface of the unit body and the fireproof covering material together, preferably with aluminum tape between them. This makes it possible to effectively reduce the total thickness and number of layers of the fireproof covering material under the floor. [Explanation of symbols]

[0037] 10,10' Fireproof floor substructure 11 Joint 11a Gap 12 Floor finishing materials 13 Fireproof coverings for floors 20,20' Fireproof Wooden Floor Unit 21,21' Unit body 22 Fireproof cladding 22a Peripheral end surface 23a Bottom layer unit fireproof coating material 23b Second layer unit fire-resistant coating material 23c Third layer unit fire-resistant coating material 24 Fireproof material receiving groove 25 Fireproof materials 50 Pillar Frame 51 Beam Frame

Claims

1. A fireproof floor base structure constructed by supporting a plurality of wooden fireproof units having a rectangular planar shape on floor beams or foundations and installing them in series, The wooden fire-resistant unit is configured to include a unit body made of a wooden material, and a fire-resistant covering material having a rectangular planar shape similar to that of the unit body, the fire-resistant covering material being attached integrally to a lower surface of the unit body while covering the lower surface of the unit body; At least one of the peripheral end faces of the fire-resistant covering material facing each other at the joints of each pair of adjacently installed wooden fire-resistant units has a fire-resistant material accommodation groove formed in an upper portion thereof, excluding a lower end edge portion in the thickness direction, in which a heat-foamable fire-resistant material and / or a heat-expandable fire-resistant material is accommodated as a fire-resistant material, the fire-resistant material accommodation groove extending in the extension direction of the joint, and the fire-resistant material is accommodated in the fire-resistant material accommodation groove without protruding from the peripheral end face, A fire-resistant floor base structure in which the fire-resistant material foams and / or expands in the event of a fire to fill the gaps in the joints.

2. The fire-resistant floor base structure described in claim 1, wherein the fire-resistant coating material is formed by stacking unit fire-resistant coating materials in a plurality of layers, and at the peripheral end surface, the end faces of one or more layers of unit fire-resistant coating materials excluding the outermost layer are stacked with a setback from the end face of the unit fire-resistant coating material of the outermost layer, so that the setback portion provides the fire-resistant material accommodating groove.

3. 3. A fireproof floor structure according to claim 1 or 2, wherein the fireproof material is a fireproof tape, a fireproof caulking material, or a fireproof paint.

4. 3. A fireproof floor base structure according to claim 1 or 2, wherein the fireproof covering material is formed using a gypsum board or a calcium silicate board.

5. A wooden fireproof unit used in the fireproof floor base structure according to claim 1, The unit is configured to include a unit body made of a wooden material having a rectangular planar shape, and a fire-resistant covering material having the same rectangular planar shape as the unit body, the fire-resistant covering material being attached integrally to cover the lower surface of the unit body, A fire-resistant material accommodating groove is formed extending in the circumferential direction on the upper portion of the peripheral end surface of the fire-resistant covering material at least on one side of the rectangular planar shape, excluding the lower edge portion in the thickness direction, and the fire-resistant material accommodating groove accommodates a heat-foamable fire-resistant material and / or a heat-expandable fire-resistant material as the fire-resistant material without protruding from the peripheral end surface.

6. The fire-resistant covering material is formed by stacking unit covering materials in a plurality of layers, and at the peripheral end surface, the end faces of one or more layers of unit covering materials excluding the outermost layer are stacked with a setback from the end face of the unit covering material of the outermost layer, thereby forming the fire-resistant material accommodating groove in the setback portion.

7. 7. The wooden fireproof unit according to claim 5 or 6, wherein the fireproof material is a fireproof tape, a fireproof caulking material, or a fireproof paint.

8. 7. The wooden fireproof unit according to claim 5, wherein the fireproof covering material is formed using a gypsum board or a calcium silicate board.

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