JP2009174301A - Eaves soffit structure, fire-proof reinforcement body and fire-proof reinforcement method for eaves soffit structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance fire-resisting performance of under-eaves in an eaves soffit structure of a building more efficiently than increasing a thickness of an eaves soffit board. <P>SOLUTION: The eaves soffit structure is provided on a rear side of the eaves of a building with an eave-soffit member 80 having predetermined fire-resistant performance and an under-eaves space S is formed at the upper part of the eave-soffit member 80. The eave-soffit member 80 is composed of an eaves soffit board 35 having predetermined fire-resistant performance and a fire-resistant reinforcement layer 81 laminated on the eaves soffit board 35. The fire-resistant reinforcement layer 81 is formed one of a thermal insulation layer 82, a heat-insulation layer 83 or a heat-absorption layer 84, or otherwise by laminating two or all the layers. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an eaves-rear ceiling structure of a building such as a house, a fireproof reinforcement body provided in the eaves-rear ceiling structure, and a fireproof reinforcement method for the eaves-rear ceiling structure.

Conventionally, in buildings such as houses, for the purpose of suppressing or preventing the spread of fire and fires due to the fire of the neighbor, fire efficiencies are required for the eaves facing the neighbor, and the silicate board with fire resistance on the back of the eaves, etc. An eaves back ceiling structure for laying a molded board (eave back ceiling board) is known (for example, see Patent Document 1).
In addition, the law on the promotion of ensuring the quality of houses (Product Quality Act) includes provisions for providing houses with fire resistance that exceeds the fire resistance specified by the Building Standards Act. In recent years, the demand has increased further, and it is desired to provide a fireproof performance that exceeds the fireproof performance for a predetermined time stipulated in the Building Standards Law for the structure of the eaves back and ceiling.
On the other hand, in order to improve the fire resistance, it is conceivable to use an eaves-backed ceiling board having an increased thickness in place of the eaves-backed ceiling board.
JP-A-6-73828

However, the thickness of the eaves-backed ceiling board as described above is generally distributed in several thicknesses, such as 8 mm, 12 mm, and 16 mm, depending on the manufacturer, and the thickness distributed on the user side. There is a problem that it is extremely difficult to prepare an eaves-back ceiling board having a thickness other than that, and it is difficult to impart desired fire resistance to the eaves-back ceiling board by increasing the thickness.
In addition, the weight of the calcium silicate board used as the eaves ceiling ceiling is generally large, and increasing the thickness of the eaves ceiling for improving the fire resistance of the eaves increases the weight of the eaves ceiling. This leads to a problem that it is necessary to improve the strength of the support structure for supporting the eaves back ceiling board.
In addition, since multiple eaves-ceiling ceiling boards are generally laid on the back of the eaves, each eaves-ceiling board is completely removed one by one to improve the fire resistance of the eaves of buildings such as existing houses. There is a problem that the work is troublesome.

Then, an object of this invention is to provide the eaves back ceiling structure which can improve the fireproof performance of an eave back more efficiently than increasing the thickness of an eaves back ceiling board.
It is another object of the present invention to provide a fireproof reinforcement that can improve the fireproof performance of the eaves back more efficiently than increasing the thickness of the eaves back ceiling board.
Furthermore, the present invention provides a fireproof performance reinforcing method for improving the fireproof performance of the eaves-in-ceiling structure of an existing building, and improves the fireproof performance of the eaves-inside structure without completely removing each eaves-backed ceiling plate from the back of the eaves. It aims at providing the fireproof performance reinforcement method which can be made to do.

As specific means for solving the above problems, the eaves ceiling structure according to the present invention is:
(1) In an eaves roof ceiling structure in which an eave roof member having a predetermined fire resistance is provided on the back side of the eaves of a building, and an eaves back space is formed above the eave roof member,
The eaves top member includes an eaves back ceiling board having a predetermined fire resistance performance, and a fireproof reinforcement layer laminated on the eaves back ceiling board, the fireproof reinforcement layer including a fireproof heat insulation layer, a heat insulation layer, It is characterized by being formed by any one layer of the endothermic layer or by laminating two or all layers.
The back of the eaves includes the back side of the eaves that protrude from the outer wall of the building, as well as the upper floor veranda provided above the lower floor and the upper side of the upper floor room, etc. The back side of the upper floor which can be looked up from the lower floor of the building formed in this way, and the ceiling part of the piloti of the building having the first floor part as a piloti are also included.

In addition, the predetermined heat resistance of the eaves back ceiling board is the eaves with the eaves back ceiling board laid down for a predetermined time even when heat is applied from below the eaves back ceiling board. This means maintaining an atmosphere at a certain temperature or lower, and there is a fireproof performance of about 30 to 45 minutes depending on the performance of the eaves back and ceiling boards.
In addition, the predetermined fire resistance performance of the eaves back ceiling board is, for example, when the eaves laid with the eaves back ceiling board are subjected to a predetermined fire resistance test prescribed by the Minister of Land, Infrastructure, Transport and Tourism, Indicates the performance that enables the temperature of the back surface of a plate (referred to as a standard plate) provided between the outer wall to be maintained at a certain temperature or lower for a predetermined time, but is specified by the Building Standards Act. Of course, and includes performance defined in all future evaluation tests.

In addition, there exists what has fireproof performance of about 30 minutes-45 minutes by the constituent material and raw material of an eaves back ceiling board.
According to the above configuration, the movement of the heat that moves (rises) to the eaves space through the eaves roof ceiling plate is suppressed by the fireproof reinforcing layer, so that the temperature rise of the eaves space is slowed down, A fire resistance higher than the fire resistance of the eaves-backed ceiling board alone can be secured.
Here, the heat transfer will be described in detail. The heat transfer includes three processes of heat conduction, heat convection, and heat radiation. Therefore, if at least one of them can be suppressed, the heat transfer can be slowed as a whole, and as a result, the time for maintaining the fire resistance performance (fire resistance time) should be extended. Can do.

Further, if the heat transfer to the eaves space itself can be reduced, the total amount of heat directed to the eaves space can be reduced, and this can also slow the temperature rise on the back surface of the eaves member. .
The fireproof heat insulating layer of the fireproof reinforcing layer is a layer capable of mainly suppressing heat conduction, and can thereby suppress the movement of heat toward the eaves space through the eaves back ceiling board. As a result, the temperature rise in the eaves back space can be slowed down.
The heat blocking layer can mainly block heat radiation excluding heat conduction and heat convection. By providing the heat blocking layer above the eaves back ceiling plate, the eaves back ceiling plate The heat radiation toward the back space and the convection heat below the heat blocking layer are securely blocked from the back of the eaves, thereby suppressing the movement of heat from the back of the eaves to the eaves. Can be made.

Further, the endothermic layer appropriately absorbs heat that enters the eaves space, and heat transferred from the eaves ceiling plate to the eaves space by stacking the endothermic layer above the eaves ceiling plate. Therefore, the movement of heat from the air layer toward the eaves space can be suppressed.
The fireproof reinforcing layer is formed by any one of the fireproof heat insulating layer, the heat shielding layer, and the heat absorbing layer, or by laminating two or all of the layers. The heat transfer toward the roof is significantly suppressed or the total amount of heat transfer is reduced, which makes it possible to significantly improve the fire resistance performance of the eaves ceiling structure using only the eaves ceiling panel. .

  In addition, since the fireproof reinforcing layer is formed thinner than the eaves-backed ceiling board, the eaves ceiling member is formed thinner than at least twice the thickness of the eaves-backed ceiling board. This increase can be eliminated by clearance and play provided in advance when the eaves-back ceiling board is held on the eaves-back. Thus, the eaves ceiling member can be attached to the eaves without changing or revising the specifications of the conventional eaves back ceiling structure that supports the eaves back ceiling board.

(2) Moreover, it is preferable that the said refractory heat insulation layer is equipped with the expansion | swelling heat insulation sheet or expansion | swelling heat insulation coating film which expand | swells by the temperature rise resulting from a fire heat, and forms the heat insulation layer of predetermined thickness.
According to this, the fireproof reinforcing layer is maintained in the form of a thin film such as a sheet or a coating film at the time of non-fire, and the thinning and weight reduction of the fireproof reinforcing layer can be improved. In addition, in the event of a fire, the sheet or coating film expands by supplying heat to the fireproof reinforcing layer to form a heat insulating layer with a predetermined thickness. The heat transfer to the door is remarkably suppressed, whereby the temperature rise in the eaves space is slowed down.

(3) Moreover, it is preferable that the said heat-shielding layer is formed with the aluminum thin film, the zinc iron plate, or the steel plate.
When the heat blocking layer is formed of an aluminum thin film, the heat blocking layer is formed to be extremely thin and lightweight, and the fireproof reinforcing body can be reduced in weight. In addition, since aluminum has a high heat reflectance (generally 97%), even if the radiant heat reaches the aluminum thin film, most of the radiant heat is reflected on the surface of the aluminum thin film. Only a small amount of radiant heat penetrates the aluminum thin film. Therefore, the aluminum thin film is suitable as a heat blocking layer mainly blocking heat radiation.

Further, when the heat blocking layer is formed of a galvanized iron plate or a steel plate, these mainly form a heat blocking layer that blocks heat convection, so that it is possible to block hot air flow and heat radiation as described above. In particular, since these zinc iron plates and steel plates have a remarkably high melting point compared to the temperature of the thermal atmosphere at the time of fire, they can maintain the plate shape without being easily melted even in the event of a fire. It can be blocked for a long time. Further, among the thermal convections, particularly hot air currents are a problem, but when these zinc iron plates and steel plates are employed as the heat blocking layer, the hot air currents can also be reliably suppressed.
The hot air current is a high-temperature air current generated at the time of a fire, and its rising speed is the maximum at the center, and is generally about 12 m / sec to 14 m / sec as an actual measured value (Architecture Dictionary ( See Shokokusha, 2nd edition).

  In addition, the aluminum thin film mainly blocks and reflects radiant heat, and naturally, convection heat can also be blocked by maintaining the film shape. Similarly, a galvanized iron plate or a steel plate mainly cuts off convective heat, and naturally can cut off radiant heat.

(4) The endothermic layer is preferably formed using aluminum hydroxide as a main material.
According to this, the endothermic layer can be formed extremely thin and lightweight, and the weight of the eaves member can be reduced. In addition, aluminum hydroxide is dehydrated at around 280 ° C., which is the atmospheric temperature at the time of fire, and thus is suitable as a layer that absorbs heat transfer at the time of fire.
(5) The endothermic layer is preferably formed by laying an endothermic bag formed by sealing aluminum hydroxide powder in a bag. When the endothermic layer is formed in the form of aluminum hydroxide, the surface area of the aluminum hydroxide is improved, and the endothermic performance can be improved. On the other hand, since it is very difficult to incorporate or construct a powdery material in a member, it is sealed in a bag, thereby making it possible to easily form an endothermic layer.

(6) As another specific means for solving the above problems, the present invention provides
In the eaves back ceiling structure in which an eaves back ceiling board having predetermined fire resistance performance is provided on the back side of the eaves of the building, and an eave back space is formed above the eaves back ceiling board,
It is preferable that the upper surface of the eaves-backed ceiling board is covered with a fireproof reinforcing body including a heat absorbing layer formed of aluminum hydroxide as a main material.
(7) In the above configuration, the endothermic layer is preferably formed by laying a sachet formed by encapsulating aluminum hydroxide powder, and (8) the refractory reinforcement is formed with the endothermic layer, It is also preferable to form it with a heat barrier layer made of aluminum.
(9) The fireproof reinforcing body is provided in the eaves back space in a state where the heat absorption layer is placed on the upper surface of the eaves back ceiling board and the heat blocking layer is stacked on the upper surface of the heat absorption layer. Is preferred.

(10) As another specific means for solving the above-mentioned problem, the fireproof reinforcing body according to the present invention is:
A fireproof reinforcement layered on an eaves roof ceiling board forming an eaves ceiling ceiling structure of a building, comprising any one of a fireproof heat insulating layer, a heat shielding layer, and an endothermic layer, or two or all of them It is characterized by being formed by laminating layers.

(11) As another specific means for solving the above-mentioned problem, the fireproof reinforcement according to the present invention is:
A fireproof reinforcing body laminated on an eaves roof ceiling board that forms an eaves roof ceiling structure of a building, and is characterized by being provided with an endothermic layer mainly composed of aluminum hydroxide.
(12) Moreover, it is preferable that the said endothermic layer is formed by laying a sachet formed by enclosing aluminum hydroxide powder. Similarly (13), it is preferable that the heat absorption layer and a heat blocking layer made of aluminum are provided. (14) It is preferable that the endothermic layer is located on the eaves back ceiling board, and the heat blocking layer is located on the endothermic layer.

(15) In addition, as a specific means for solving the above problems, a fireproof reinforcing method for an eaves-backed ceiling structure according to the present invention is:
A plurality of eaves-backed ceiling boards with a predetermined fire resistance performance are laid out along the eaves direction of the eaves to form an eaves-back space, and the side edges along the outer wall of the building are the outer walls. A fireproof reinforcement method of the eaves back ceiling structure that is held by the eaves mounting hardware that is held by the mounting eaves and the side edge along the eaves is supported by the eaves,
Remove one of the mounting hardware to release the holding state of one side edge of the eaves back ceiling board,
The upper side of the eaves back ceiling board is exposed by swinging the eaves back ceiling board in the downward direction with the other side edge as the swing axis,
Laying fireproof reinforcement on the upper surface of the eaves back ceiling plate,
After swinging the eaves-back ceiling plate in the upward direction around the swing axis, the one mounting hardware is attached to make one side edge of the eaves-back ceiling plate again held. .
According to the above configuration, the one side edge of the eaves back ceiling board is laid on the upper surface of the eaves back ceiling board in a state where it is held in the mounting hardware before and after the fireproof reinforcement body is laid. Is possible.

According to the eaves-in-ceiling structure of the present invention, the fireproof performance of the eaves can be improved more efficiently than when the thickness of the eaves-interior ceiling plate is increased.
Moreover, according to the reinforcement heat insulating body of this invention, the fireproof performance of an eaves back can be improved efficiently rather than increasing the thickness of an eaves back ceiling board.
According to the fireproof performance reinforcing method of the present invention, it is possible to improve the fireproof performance of the eaves back structure without completely removing each eaves back ceiling board from the back of the eaves.

Hereinafter, based on FIGS. 1-20, it demonstrates in detail about embodiment which employ | adopted this invention for the two-story detached house.
In addition, about FIG.1 and FIG.2, it is drawing about 1st Embodiment which employ | adopted the eaves-back ceiling structure of this invention for the house which has a dormitory roof, Comprising: FIG. FIG. 4 is a drawing of a second embodiment adopting the eaves-rear ceiling structure of the invention, and FIGS. 4 and 5 are diagrams showing a procedure for providing the eaves-rear ceiling structure of the present invention in an existing house having a dormitory roof. 6 and FIG. 7 show the third embodiment of the eaves-rear ceiling structure, and FIG. 8 is a cross-sectional view of the main part of the eaves-rear ceiling structure for explaining a modification of the third embodiment. 9 and 10 are drawings of a fourth embodiment in which the eaves-backed ceiling structure of the present invention is adopted for a house having a flat roof, and FIGS. 11 to 15 are drawings of experiments on examples of the present invention. 16 and 17 show the configuration of the test body of Example 3. A to cross-sectional views, FIGS. 18 and 19 are graphs showing test results of Example 3, FIG. 20 is a graph showing the test results of Example 4.

<First Embodiment>
A detached house 1 according to the present invention is a house 1 having a so-called dormitory roof, a frame 1a formed by combining lightweight steel frames, and an outer wall structure 1b attached to the frame 1a to form the side surface of the house. The roof structure 1c is attached to the frame 1a to form the upper surface of the house.
The frame 1a is configured as a frame structure formed by including a plurality of column members and face members erected on the foundation B and beam members that connect the column members and face members. The column material is formed by attaching a steel head pipe or a column head member or a column base member to the end portion of the square pipe, and the face material is formed by connecting a pair of square pipes by braces or a vibration control frame. . The beam material is formed of an H-shaped steel or a steel square pipe.
The outer wall structure 1 b includes a flat outer wall 2 and a heat insulating layer (not shown) provided on the indoor side of the outer wall 2.

The outer wall 2 is formed by arranging a plurality of outer wall materials formed of flat lightweight cellular concrete (ALC) panels in parallel. Each outer wall material is supported by the beam via a metal fitting (not shown) such as a self-weight receiving metal fitting or an inazuma plate attached to the beam constituting the outermost frame of the frame 1a.
Since the ALC panel is light and has high heat insulation performance, it can be preferably used as an outer wall material.

Moreover, as shown in FIG. 1, the detached house 1 which concerns on this invention is formed so that a bottom may protrude with respect to a bookstore, and the roof structure 1c is a one-floored 1st floor roof which forms the roof of a bottom in the upper part. 3 and a gable-shaped second-floor roof 4 forming a second-floor roof. Each roof 3, 4 includes an eave 5 at a position protruding outward from each outer wall 2 located below the roofs 3, 4, whereby the eave 5 and the outer wall 2 of each roof 3, 4 An eaves space S is formed between them.
For the convenience of description of the embodiment, the direction perpendicular to the paper surface (normal direction) in FIG. 1 is referred to as a carry direction, and the direction parallel to the paper surface in FIG.
Since the structures of these eaves 5 are substantially the same, the configuration of the eaves 5 on the second floor will be described below, and the description of the eaves 5 on the first floor will be omitted.

As shown in FIG. 2, the eave 5 includes an eaves tip structure 10 that protrudes from the outer wall 2 of the second floor portion, and an eaves back ceiling structure 30 that closes the eaves back space S surrounded by the eaves tip structure 10. ing.
In addition, the protruding dimension of the eaves is preferably 2000 mm or less, and most preferably 1000 mm or less. In this embodiment, the protruding dimension L of the eave is 720 mm.
The eaves-end structure 10 includes an eaves roof 11 that forms a roof, a rafter member 12 that supports the eaves roof 11, a joint hardware 13 attached to a tip portion of the rafter member 12, and the joint hardware 13. And a nose cover member 14.

The eaves roof 11 includes a base plate 16 made of a flat structural plywood, and a roof plate member 17 laid on one surface (upper surface) of the base plate 16.
The rafter member 12 that supports the eaves roof 11 is formed as a long member having a U-shaped cross section by pressing a flat metal plate. Further, a plurality of rafter members 12 are installed in a downwardly inclined manner from the ridge toward the eaves with a predetermined interval in a state where the longitudinal direction is in the direction between the beams. In addition, each rafter member 12 is supported by an eaves girder 2b forming a frame 1a through a hardware member k1 in the middle.
The joint hardware 13 includes a connecting portion 18 that is connected to the distal end portion of the rafter member 12, and a hanging portion 19 that is suspended from the connecting portion 18.

The nose cover member 14 is formed of a flat plate-like structural plywood similar to the base plate 16 and is attached to the hanging portion 19 of each joint hardware 13 via a tapping screw or the like in a state of straddling the plurality of joint hardware 13. It has been. Further, the nose mask member 14 is attached to the joint hardware 13 with the upper end edge along the inclined surface 12 a formed by the upper end surface of the rafter member 12, so that the lower end portion of the nose mask member 14 is 2 It faces the upper end of the outer wall 2 of the floor portion.
Further, on one surface (front surface) of the nose cover member 14, an eaves bowl 15 that receives rainwater and the like flowing down the roof plate member 17 is attached.
By arranging the members 10 to 14 as described above, the eaves 5 is formed with an eaves back space S surrounded by the eaves beam 2b, the base plate 16 of the eaves roof 11, and the nose cover member 14. The eaves back ceiling structure 30 is a structure that closes the eaves back space S from below.

  By the way, in a city where houses 1 are densely populated, a fire occurs in a certain house 1 and the flame of the fire burns out to a neighbor adjacent to the house 1 (this phenomenon is called fire spread or fire). There is a risk of getting involved in a fire. It is known that the spread of fire to such a neighboring house is that the eaves 5 and the like protruding from the outer wall 2 are exposed to the heat of fire for a considerable time, and the eaves 5 are burned. In order to prevent this kind of fire spread, the back of the eave is required to have a predetermined fire resistance.

  The eaves back ceiling structure 30 of the present embodiment improves the fire resistance required for the back of the eaves as described above, and includes an L-shaped hardware 31 attached to the lower end portion of the nose cover member 14, and the L-shape. An eaves attachment hardware 32 supported by the metal fitting 31, an outer wall attachment hardware 33 connected to a Z hardware k2 attached to the lower end of the eaves girder 2b and supporting the outer wall 2, and these eaves attachment hardware 32 and the outer wall attachment hardware. And an eaves top member 80 that is installed over the eaves edge mounting hardware 32 and the outer wall mounting hardware 33 and is suspended from the field edge assembly 34.

The L-shaped hardware 31 is attached to the lower end portion of the nasal concealment member 14 in a state where the longitudinal direction coincides with the carry direction, and one side of the nasal concealment member 14 (the front surface in the present embodiment). And a horizontal plate portion 38 that protrudes horizontally from the lower end of the connection plate portion 37 toward the outer wall 2.
The eaves mounting hardware 32 includes a U-shaped mounting portion 40 that is fastened to the horizontal plate portion 38 of the L-shaped hardware 31 via a bolt or the like, and a flat parting plate 42 that is attached to the lower portion of the mounting portion 40. And. When the attachment portion 40 is attached to the horizontal plate portion 38 of the L-shaped hardware 31, the lower surface of the horizontal plate portion 38 and the upper surface of the parting plate 42 face each other in a parallel state.

The outer wall fitting 33 is formed by pressing a metal plate or the like, and is formed at the tip of the bracket 43 with a bracket 43 connected to the Z metal k2 supporting the outer wall 2 via a tapping screw or the like. The eaves-top holding part 46 is provided. The bracket portion 43 has a vent hole 44a in the flat plate portion.
In addition, the eaves-top holding part 46 includes a pair of holding pieces 47 and 47 and a connecting part 48 that connects the pair of holding pieces 47 and 47. Further, when the outer wall mounting hardware 33 is attached to the Z hardware k2, one surface of the connecting portion 48 of the eaves holding part 46 is opposed to the outer wall 2 with a predetermined interval. A thermal expansion material 49 is attached which expands in the thickness direction until it reaches a predetermined thickness when the temperature reaches a predetermined temperature due to heat.

Moreover, the attachment part 40 of the eaves-end attachment hardware 32 and the connection part 48 of the outer wall attachment hardware 33 have the same height. The height is the same as or slightly larger than the thickness of the eaves back ceiling board 35. Further, the upper surface of the parting plate 42 of the eaves-end fitting 32 and the upper surface of the holding piece 47 below the outer wall fitting 33 are set at the same height.
The field edge assembly 34 includes a field edge receiver 51 that is supported by the outer wall mounting hardware 33, and a plurality of field edges 52 that spans the field edge receiver 51.
The field edge receiver 51 is formed as a long member having a U-shaped cross section formed by pressing a metal plate, and an upper surface portion 54 is bent at one end of the flat side surface portion 53 and a lower surface portion 55 at the other end. Is bent, and the side surface portion 53 is attached to the bracket portion 43 of the outer wall fitting 33 through a tapping screw or the like.
The field edge 52 is formed in a rectangular tube shape formed by press-molding a metal plate, and is installed along the beam-to-beam direction, with one end portion of the upper and lower surface portions 54, 55 and the side surface portion 53 of the field edge receiver 51. It is attached to the field receiver 51 with a tapping screw or the like in a state of being fitted in between, and the other end is placed on the upper surface of the horizontal plate portion 38 of the L-shaped hardware 31.

  The eaves ceiling member 80 is formed by including an eaves back ceiling plate 35 and a fireproof reinforcing layer 81 laminated on the eaves back ceiling plate 35, and the side edge on the eaves side is the horizontal side of the L-shaped hardware 31. The eaves are sandwiched between the plate portion 38 and the parting plate 42 of the eaves-end fitting 32, and the side edge on the outer wall side is held between the pair of clamping pieces 47, 47 of the eaves top holding portion 46 of the outer wall fitting 33. It is provided on the back side, thereby closing the eaves space S from below. The eaves member 80 is fastened to the horizontal plate part 38 of the L-shaped hardware 31 via a tapping screw or the like whose one side edge is screwed from below the eaves member 80, and the other plural The portion is fastened to the field edge 52 of the field edge assembly 34 via a tapping screw or the like screwed from below the eaves ceiling member 80.

The eaves back ceiling board 35 is formed of a flat fiber-mixed calcium silicate board having a predetermined fire resistance, and the thickness of the calcium silicate board is preferably 6 mm to 16 mm, from the viewpoint of fire resistance. Most preferred is a thickness of 16 mm.
Here, the predetermined fire resistance performance of the eaves back ceiling board 35 is, for example, when a predetermined fire resistance test stipulated by the Minister of Land, Infrastructure, Transport and Tourism is performed on the eaves 5 on which the eaves back ceiling board 35 is laid. The performance of enabling the temperature of the back surface of a plate (referred to as a standard plate) provided between the eaves back space S and the outer wall 2 of the eave 5 to be maintained in an atmosphere below a certain temperature for a predetermined time. However, it naturally includes the performance defined by the Building Standards Law, and also includes performance defined in all evaluation tests defined in the future.

In this embodiment, a fiber-mixed calcium silicate board is adopted as the eaves-back ceiling board 35, but the eaves-back ceiling board 35 is replaced with a fiber-mixed calcium silicate board, and a fiber-mixed cement calcium silicate board. Ceramic siding boards such as fiber reinforced cement board, lime / calcium silicate board, hard wood piece cement board, etc. are used, and the thickness as the eaves ceiling board 35 is 6mm to 25mm depending on the required fire resistance performance and material Selected between degrees.
Moreover, the heat insulation performance of the eaves back ceiling board 35 formed with the said fiber mixed calcium silicate board of thickness 16mm has fire resistance performance of about 35 to 45 minutes, and the fireproof reinforcement layer 81 is the said eaves back ceiling board. Complementing the fireproof performance of 35, the fireproof time of the entire eaves-backed ceiling structure 30 is extended.

The fireproof reinforcing layer 81 suppresses the movement of heat toward the eaves space S through the eaves back ceiling plate 35. The fireproof time of the eaves back ceiling plate 35 alone is reduced by slowing the temperature rise in the eaves space S. The fire resistance time is extended more than that, and the fire resistance performance higher than the fire resistance performance of the eaves back ceiling board 35 alone is ensured.
Here, the heat transfer will be described in detail. The heat transfer includes three processes of heat conduction, heat convection, and heat radiation. Therefore, if at least one of them can be suppressed, the heat transfer can be slowed as a whole, and as a result, the time for maintaining the fire resistance performance (fire resistance time) should be extended. Can do.

On the other hand, if the heat toward the eaves space S can be absorbed, the total amount of heat toward the eaves space S can be reduced, which also suppresses the temperature rise in the eaves space S. The
Therefore, the fireproof reinforcing layer 81 is preferably formed of any one of a fireproof heat insulating layer, a heat blocking layer, and an endothermic layer, or a laminate of two or all layers. The fire-resistant reinforcing layer 81 includes a fire-resistant and heat-insulating layer 82 laminated on the upper surface of the eaves back ceiling board 35 and a heat-shielding layer 83 laminated on the upper surface of the fire-resistant and heat-insulating layer 82.
The fire-resistant and heat-insulating layer 82 of the fire-resistant reinforcing layer 81 is a layer capable of mainly suppressing heat conduction, whereby heat flowing toward the eaves space through the eaves-backed ceiling plate 35 by the fire-resistant reinforcing layer 81. Movement is suppressed.

In the present embodiment, the fireproof heat insulating layer 82 is installed in a state of covering the eaves back ceiling board 35 and foams and expands in the thickness direction when a predetermined temperature is reached by the heat to form a predetermined heat insulating layer. An expansion heat insulation sheet is used.
The expanded heat insulating sheet is formed into a sheet shape in which a foamed pigment such as graphite powder is hardened with a resin binder such as epoxy resin or butyl, and expands and expands when it reaches a predetermined temperature by heating. It is an organic refractory material that demonstrates The expanded thermal insulation sheet does not expand under a normal temperature environment and expands by expanding to about 5 to 40 times in the thickness direction when heated to 200 ° C. or more, and the foaming residue due to the expansion is used as a thermal insulation layer. be one that functions, the thickness under normal temperature environment and weight 1.2kg / m ² ~2.0kg / m ² approximately with the order of 1 mm to 5 mm, 5 to 30 times by the high temperature atmosphere during fire Those that swell are preferred. In this embodiment, this type of heat-insulating expansion sheet has a thickness of 2 mm in normal time (non-fire) and a weight of 1.8 kg / m ² , and expands about 10 times in the thickness direction by heating. A block (registered trademark Fiblock. Trademark owner: Sekisui Chemical Co., Ltd.) is used.

In addition, as a heat insulation expansion sheet, it is not limited to the said fibro but other heat-expandable heat insulation sheets of an inorganic type or an organic type are also employable. Moreover, it is also possible to employ | adopt the heat expansion coating film which expands by heating instead of a heat insulation expansion sheet.
The heat blocking layer 83 mainly blocks heat radiation and heat convection excluding heat conduction. By providing the heat blocking layer 83 above the refractory heat insulating layer 82, the eaves back ceiling plate 35 and the eaves back space The heat radiation toward S and the convection heat reaching the heat blocking layer 83 through the fireproof heat insulating layer 82 are surely blocked from passing into the eaves space S, and this greatly increases the heat transfer toward the eaves space S. It is possible to suppress it.

In the present embodiment, an aluminum thin film (aluminum foil) having a thickness of about 0.2 mm and a weight of about 0.5 kg / m ² is used as the heat blocking layer 83, and thereby, the heat blocking layer 83 is used. Is extremely thin and lightweight, and the refractory reinforcement layer 81 can be reduced in weight.
In addition, since aluminum has a high thermal reflectance (generally about 97%), even when the radiant heat reaches the aluminum thin film, most of the radiant heat is reflected on the surface of the aluminum thin film, so that it is very slight. The radiant heat only penetrates the aluminum thin film, whereby the movement of heat to the eaves space S through the eaves ceiling member 80 is suppressed, and as a result, the temperature rise in the eaves space S is slowed down.

In addition, it is preferable to employ | adopt about 0.1-1.0 kg / m < ² > as aluminum foil, and the unit equivalent to the said aluminum foil other than the aluminum glass cloth etc. which reinforced aluminum foil with glass fiber is also preferable. It is also preferred to use by weight.
According to the present embodiment, since the fireproof reinforcing layer 81 including the fireproof heat insulating layer 82 and the heat blocking layer 83 is provided on the eaves top member 80, the heat reaching the eaves back space S via the eaves top member 80 is reduced. The movement is suppressed, and thereby the fire resistance performance can be improved more than the fire resistance performance of the eaves ceiling structure using only the eaves roof ceiling plate 35.

Further, 2.3 mm relative to the weight of the soffit ceiling board 35 that is ^{2 ~16.0kg} / m ² about 13.0 kg / m, refractory reinforcing layer 81, an even thickness by summing the two layers ～2.7Mm, it is for the weight of 2.0kg / m ² ~2.5kg / m ² approximately. Therefore, the eaves ceiling member 80 formed by laminating the fireproof reinforcing layer 81 on the eaves back ceiling board 35 is only slightly increased in thickness and weight compared to the eaves back ceiling board 35 alone. Therefore, it will exhibit high heat insulation performance, and it has a lower weight than the case where the eaves back ceiling board 35 is laminated and has fire resistance equivalent to or higher than that of the eaves back ceiling board 35 laminated. It will have. As a result, the eaves ceiling member 80 can be attached to the eaves without changing or refurbishing the frame structure of the building that supports the eaves back ceiling board 35 alone.

The fireproof heat insulating layer 82 expands in the thickness direction due to the heat, but the portion sandwiched between the eaves ceiling plate 35 and the field edge 52 by the tapping screw or the like is thick enough to resist the clamping force. There is no possibility that the connected state between the eaves back ceiling board 35 and the field edge 52 is released by the expansion.
Further, when the surrounding area under the eaves becomes a predetermined temperature atmosphere due to heating such as a fire, the heating expansion material 49 of the eaves top holding part 46 of the outer wall mounting hardware 33 expands and reaches the outer wall 2. As a result, the air hole 44a is blocked by the heat expansion material 49, the inflow of the hot airflow through the air hole 44a is suppressed, and the temperature rise of the eaves space S is also suppressed.

Second Embodiment
In this embodiment, since it is the same as that of the said 1st Embodiment except the structure of the eaves back ceiling structure 30, the same code | symbol as the said 1st Embodiment is attached | subjected and the description is abbreviate | omitted.
In the present embodiment, as shown in FIG. 3, the eaves back ceiling structure includes an L-shaped hardware 31 attached to the lower end portion of the nose cover member 14, and an eaves tip mounting hardware 32 suspended from the L-shaped hardware 31. An outer wall mounting hardware 33 attached to the lower end of the eaves beam 2b and connected to the Z hardware k2 supporting the outer wall 2, a field edge assembly 34 assembled between the eaves mounting hardware 32 and the outer wall mounting hardware 33, and an eaves edge An eaves-back ceiling plate 35 that spans the attachment hardware 32 and the outer wall attachment hardware 33 and is suspended from the field assembly 34, and a fireproof reinforcement 81 a that is placed on the eaves-back ceiling plate 35. .
That is, in the present embodiment, the eaves back ceiling board 35 and the fireproof reinforcing layer 81 of the first embodiment are used as separate members, and the fireproof reinforcing layer 81 is formed as a member as a fireproof reinforcing body 81a. The reinforcing body 81a complements the fireproof performance of the eaves-back ceiling plate 35 and extends the fireproof time of the entire eaves-back ceiling structure.

In FIG. 3, for convenience of explanation, a gap is provided between the eaves back ceiling board 35 and the fireproof reinforcing body 81 a, but actually the fireproof reinforcing body 81 a is mounted on the eaves back ceiling board 35. Therefore, there is almost no gap between the two members 35 and 81a.
Since the structure of each layer of the fireproof reinforcement 81a is the same as that of the fireproof reinforcement layer 81 of the first embodiment, description thereof is omitted.
The configuration of the present embodiment is as described above. Next, with reference to FIGS. 4 and 5, an existing eaves ceiling structure 30 that holds only the eaves ceiling plate 35 with the attachment hardware 32, 33 is used. A method of installing the fireproof reinforcement 81a on the eaves 5 as described above will be described.

  As shown in FIG. 4A, first, the eaves attachment hardware 32 is removed, and the support of the eaves back ceiling board 35 by the field edge assembly 34 is released. Thereby, the eaves back ceiling board 35 will be in the state hold | maintained only at a pair of clamping pieces 47 and 47 of the eaves top holding | maintenance part 46 of the outer wall attachment hardware 33. FIG. Here, the connection between the eaves attachment hardware 32 and the eaves back ceiling board 35 and the L-shaped hardware 31 or the connection between the eaves back ceiling board 35 and the field edge 52 of the field edge assembly 34 is performed under the eaves back ceiling board 35. Since it is fastened from the side via a tapping screw or the like, the connected state of each member can be easily released by removing each tapping screw from below the eaves back ceiling plate 35 (under the eaves).

  In addition, there is a slight gap between the pair of sandwiching pieces 47, 47 and the eaves ceiling plate 35 for the purpose of eliminating construction errors, etc. The side wall portion on the outer wall side accommodated in the outer wall fitting 33 is used as a swinging shaft, and the side edge portion on the eaves side is used as a free end to swing freely. In this state, the side edge portion on the eaves side of the eaves back ceiling board 35 is pushed down to expose the upper surface of the eaves back ceiling board 35 as shown in FIG. Here, when the outer wall side edge of the eaves back ceiling plate 35 is sandwiched by the eave ceiling holding portion 46 of the outer wall attachment hardware 33 without a gap, the outer wall attachment hardware 33 is also moved along with the swinging of the eaves back ceiling plate 35. If the outer wall mounting hardware 33 is formed of a metal plate rich in toughness, the deformation of the swinging degree is within the range of elastic deformation, and the eaves ceiling plate 35 is restored to its original shape. By returning to the position, it is possible to easily return to the original shape.

Then, as shown in FIG. 5 (a), a fireproof reinforcing body 81a is laid on the upper surface of the eaves back ceiling board 35. At this time, since the fireproof reinforcing body 81a is formed in a sheet shape having a thickness of about 2.0 mm to 3.0 mm, it is bulky even if the fireproof reinforcing body 81a is laid on the upper surface of the eaves back ceiling plate 35. There is no fear of becoming. Moreover, since the clearance gap is provided between the eaves back ceiling board 35 and the clamping piece 47 of the eaves top holding | maintenance part 46 of the outer wall attachment hardware 33, the fireproof reinforcement 81a is inserted also in the said clearance gap. By the construction, the upper surface of the eaves back ceiling board 35 is covered over the entire surface by the fireproof reinforcing body 81a.
Thereafter, as shown in FIG. 5 (b), the side edge of the eaves back ceiling board 35 on the eaves side is pushed up to hold the eaves back ceiling board 35 in a horizontal state, and the eaves mounting hardware 32 removed earlier is attached again. The side edge of the eaves back ceiling board 35 and the fireproof reinforcement 81a are sandwiched between the seat part of the eaves attachment hardware 32 and the horizontal plate part 38 of the L-shaped hardware 31. Also here, since the fireproof reinforcing body 81a is thinly formed as described above, there is no possibility that the holding state of the eaves back ceiling board 35 by the eaves mounting hardware 32 is hindered due to the thickness of the fireproof reinforcing body 81a. .

Finally, the eaves back ceiling board 35 and the field edge 52 of the field edge assembly 34 are fastened again with a tapping screw or the like. As a result, the fireproof reinforcing body 81a is sandwiched between the eaves back ceiling board 35 and the field edge 51 of the field edge assembly 34.
According to this embodiment, the fireproof reinforcing body 81a is laid on the upper surface of the eaves back ceiling board 35 without completely removing the eaves back ceiling board 35 from the back of the eaves. Since one side edge of the eaves back ceiling board 35 is held by the mounting hardware 32, 33 before and after the fireproof reinforcement body 81a is laid, the weight of the eaves back ceiling board 35 is reduced. The part is borne by the building (frame structure) via the outer wall mounting hardware 33, and thus the eaves back ceiling board 35 can be easily handled. Moreover, since construction can be performed only by removing one eaves-end fitting hardware 32 out of both the fittings 32 and 33, the construction time can be shortened.

<Third Embodiment>
Although the present embodiment is different from the first embodiment in the configuration of the fireproof reinforcing body 81a, the other configurations are the same as those in the first embodiment, and the configuration other than the fireproof reinforcing body 81a is the same as that in the first embodiment. The description is abbreviate | omitted and attached | subjected.
As shown in FIG. 6, the fireproof reinforcing body 81 a of the present embodiment includes a heat shielding layer 83 provided on the upper surface of the eaves back ceiling board 35, and a heat absorbing layer 84 laminated on the upper surface of the heat shielding layer 83. It is configured.
In the present embodiment, an aluminum thin film (aluminum foil) having a thickness of about 0.2 mm and a weight of about 0.5 kg / m ² is used as the heat blocking layer 83. In addition, the heat shielding layer 83 has one side edge portion that wraps around the upper surface portion 53 of the field edge 52 of the field edge assembly 34 and wraps around the back surface side of the side surface portion 53, and the other side edge portion is L-shaped. It is provided in a state where the upper surface of the horizontal plate portion 38 of the hardware 31 is covered.

In addition, it is preferable to employ | adopt about 0.1-1.0 kg / m < ² > as aluminum foil, and the unit equivalent to the said aluminum foil other than the aluminum glass cloth etc. which reinforced aluminum foil with glass fiber is also preferable. It is also preferred to use by weight.
The endothermic layer 84 absorbs heat transfer from the heat blocking layer 83, and the total amount of heat transferred to the eaves space S is reduced by the endothermic layer 84. The temperature rise is slowed down.

In the present embodiment, the heat absorption layer 84 is formed by connecting a plurality of heat absorption bags 87 formed by enclosing the powdered aluminum hydroxide in a bag formed of a polyester nonwoven fabric or the like. In each bag, powdered aluminum hydroxide having a weight of about 5.0 kg / m ² is enclosed in a thickness of about 5 mm to 10 mm. When the aluminum hydroxide powder is used as the endothermic layer 84, it is preferably used at a unit weight of about 0.5 to 6.0 kg / m ² , taking into account the balance with the weight applied to the eaves ceiling structure 30. Therefore, it is most preferable to use the unit weight of about 5.0 kg / m ² . In addition, by forming the endothermic layer 84 with the plurality of endothermic bags 87 in this way, handling of powdered aluminum hydroxide used as the endothermic layer 84 becomes easy. Moreover, since aluminum hydroxide dehydrates at around 280 ° C., which corresponds to the vicinity of the temperature of the thermal atmosphere during a fire, it effectively absorbs heat transfer from the heat blocking layer 83 during the fire.

Also in the present embodiment, the movement of heat to the eaves space S via the eaves back ceiling plate 35 is remarkably slowed down, so that the fire resistance performance of the eaves back ceiling structure 30 using only the eaves back ceiling plate 35 is higher. Improvement is achieved.
In addition, the configuration of the present invention is not limited to the above embodiment, and configurations other than the above embodiment can also be adopted.
For example, a metal plate such as a zinc iron plate or a steel plate can be used as the heat blocking layer 83. The metal plate preferably has a thickness of about 0.1 mm to 1.0 mm, and most preferably about 0.27 mm. Since the metal plate as the heat blocking layer 83 mainly forms a heat blocking layer that blocks heat convection, it is possible to block the hot air flow. In particular, these zinc iron plates and steel plates have a remarkably high melting point compared to the temperature of the thermal atmosphere at the time of the fire, so that the plate shape is maintained without being easily melted even at the time of the fire. Is also blocked for a long time.

The hot air flow is a high-temperature air flow that is generated in the event of a fire, and its rising speed is the largest at the center, and is actually 12 to 14 m / sec (Architectural Dictionary (Akuni) Company, 2nd edition)).
In addition, the aluminum foil of the above embodiment mainly shields / reflects radiant heat, and can naturally block convection heat by maintaining a film shape. Of course, the plate mainly cuts off convective heat, and naturally cuts off radiant heat.
In addition, when aluminum hydroxide is used as the endothermic layer 84, it is possible to spray aluminum hydroxide powder, and of course, a coating film containing aluminum hydroxide or aluminum hydroxide powder was fixed with an adhesive. Of course, the endothermic layer 84 can be formed of a fixing film, a paper body containing aluminum hydroxide as a component, or an aluminum hydroxide powder fixing resin film. The aluminum oxide may be formed in any manner as long as a capacity of about 5.0 kg / m ² is secured.

Further, the layer structure of the fireproof reinforcing body 81a is not limited to the above embodiment, and at least one of the fireproof heat insulating layer 82, the heat blocking layer 83, and the heat absorbing layer 84 may be included. For example, the vertical positional relationship and the number of layers can be appropriately changed as necessary.
Therefore, as shown in FIG. 7, it is possible to employ those with rockwool thickness 25mm~50mm density 60kg / m ³ ~200kg / m ³ as an insulating refractory layer 82, the density and thickness of 50 mm 60 kg / it is preferred that m ³ of rock wool or rock wool density 200 kg / m ³ to 25mm thick is employed as the insulating refractory layer 82. In the said structure, the fireproof reinforcement 81a comprises the eaves back ceiling structure 30, and is filled with the space between the field edge assemblies 34 provided at equal intervals in the beam direction.

Further, a heat-insulating layer 82 made of rock wool is laminated on the heat-insulating layer 83 made of aluminum foil, a heat-insulating layer 83 made of a zinc iron plate is laminated on the fire-resistant insulating layer 82, and the upper surface of the heat-insulating layer 83 Alternatively, a configuration in which an endothermic layer 84 composed of an endothermic bag 87 is placed is also possible.
Moreover, the structure which mounts the heat absorption layer 84 which consists of heat absorption bags 87 on the heat-insulation layer 83 which consists of a zinc iron plate is also employable, and it replaces with this heat absorption layer 84, and laminates | stacks the fireproof heat insulation layer 82 which consists of a heat expansion material. A configuration can also be employed.

FIG. 8 shows a modification of the third embodiment, which is a heat-absorbing layer installed on the eaves back ceiling board 35 as a fireproof reinforcing body 81a installed on the eaves back ceiling board 35. 84 and a heat blocking layer 83 provided on the endothermic layer 84.
In the refractory reinforcement 81a, as in the third embodiment, the heat absorption layer 84 includes a plurality of heat absorption bags 87 formed by encapsulating powdered aluminum hydroxide in a bag formed of a polyester nonwoven fabric or the like. Those connected individually are used. In order to exhibit predetermined fire resistance, it is preferable to form the endothermic layer 84 with powdered aluminum hydroxide having a weight of about 5.0 kg / m ^2. On the other hand, in order to ensure workability, the entire fire resistant reinforcement 81a A configuration that can be appropriately bent and stretched as necessary is preferable. As a configuration that can achieve both of these, in the present embodiment, the bag body is formed in a rectangular shape of about 10 cm × 15 cm in plan view and is formed on the bag body. An endothermic bag 87 is formed by enclosing about 75 g of aluminum hydroxide, and a plurality of endothermic bags 87 are connected in the longitudinal direction to form an endothermic body, and the endothermic body in the width direction is further formed. The endothermic layer 84 is formed by connecting a plurality.
The heat shielding layer 83 is made of an aluminum glass cloth in which an aluminum thin film having a thickness of about 0.2 mm and a weight of about 0.05 kg / m ² is reinforced with a glass cloth having a thickness of about 0.1 mm. Yes. The heat shielding layer 83 is provided in a state of completely covering the upper surface of the endothermic layer 84, and an overlap margin covering the upper surface of the eaves ceiling structure 30 such as the field edge 52 is provided on the peripheral portion of the heat shielding layer 83. Is provided.
In the fireproof reinforcing body 81a, the heat blocking layer 83 and the heat absorbing layer 84 are integrated by being connected by staples or the like at a plurality of positions. Thus, the heat absorbing layer 84 and the heat shielding layer 83 are simultaneously formed by simply laying the fireproof reinforcing body 81a on the eaves back ceiling board 35, and the fireproof reinforcing layer 81 can be easily formed on the eaves back ceiling board 35. Is possible. Moreover, in this embodiment, since both the heat absorption layer 84 and the heat insulation layer 83 have flexibility, it is possible to bend and stretch appropriately according to construction, and to the eaves back ceiling board 35. Not only can it be installed easily, but it can be positioned appropriately following the uneven shape on the eaves back ceiling board 35 such as the edge 52 just by installing it on the eaves back ceiling board 35, and the workability is also extremely high. It will be expensive.
The size and shape of the endothermic bag 87 forming the endothermic layer 84, the capacity and particle size of the aluminum hydroxide, the thickness and weight of the heat blocking layer 83, etc. are appropriately changed according to the required fire resistance. It is also possible. In addition, the length of the fireproof reinforcing body 81a in the direction between the beams can be changed as appropriate, and not only can the configuration in which one fireproof reinforcing body 81a is provided in the direction between the beams as in the present embodiment, but also the size in the direction between the beams. It is also possible to employ a configuration in which a plurality of fireproof reinforcing bodies 81a having a reduced size are arranged. Similarly, it is possible not only to use the fireproof reinforcing body 81a corresponding to the laying length of the eaves back ceiling board 35 with one fireproof reinforcing body 81a, but also to use a plurality of fireproof reinforcing bodies 81a. It is also possible to adopt a configuration in which the eaves-backed ceiling plate 35 is covered in the laying direction by laying the fireproof reinforcing bodies 81a side by side in the direction of the laying.

<Fourth embodiment>
As shown in FIG. 9, a detached house 1 according to the present invention is a house 1 having a so-called flat roof, a frame 1 a formed by combining lightweight steel frames, and attached to the frame 1 a to form a side surface of the house. An outer wall structure 1b and a roof structure 1c attached to the frame 1a and forming the upper surface of the house are provided.
The frame 1a is configured as a frame structure formed by including a plurality of column members and face members erected on the foundation B and beam members that connect the column members and face members.
The outer wall structure 1 b includes a flat outer wall 2 and a heat insulating layer (not shown) provided on the indoor side of the outer wall 2.
The outer wall 2 is formed by arranging a plurality of outer wall materials formed of a flat lightweight aerated concrete (ALC) panel in parallel.
The roof structure 1c is formed as a so-called flat roof formed by horizontally laying flat lightweight cellular concrete panels, and includes an eave 5 that protrudes from the outer wall 2 of the second floor portion.

As shown in FIG. 10, the eaves 5 includes an eaves structure 10 that protrudes from the outer wall 2 of the second floor portion, a support structure 20 that supports the eaves structure 10, and an eaves back that is surrounded by the eaves structure 10. An eaves back ceiling structure 30 that closes the space S is provided.
The support structure 20 is constructed between a pair of pillar members and supports an outer wall 2 and a roof plate 2c on the second floor portion, and an eaves beam 21 extending from the eaves beam 2b toward the outer side of the outer wall 2. And an eaves girder 22 for connecting the leading ends of the carry-out beams 21 to each other. These beams 21 and girders 2b and 22 are connected by providing a joint piece (not shown) between the beams or between the beams and the girders and fastening the beams, girders and the joint pieces with bolts or the like.

The eaves end structure 10 includes an eaves plate member 23 erected from the eaves girder 2b to the eaves end girder 22 of the support structure 20, an accessory member 24 attached to the tip of the eaves plate member 23, and the accessory member 24 A nose cover member 25 is provided which is positioned below and extends downward from the upper end of the eaves girder 22 to the lower end of the eaves girder 22.
The eaves plate member 23 is formed of a flat lightweight aerated concrete (ALC) panel. Further, rigid floor hardware is attached to the upper surfaces of the eaves girder 2b and eaves girder 22, and mortar is filled between the rigid floor hardware and the eaves plate member 23. Moreover, the cotter (illustration omitted) is attached between the adjacent eave board members 23, and these adjacent eave board members 23 are connected through the cotter and the mortar.

The accessory member 24 is fastened to the upper end portion of the eaves girder 22 via a bolt or the like, and is flattened at a right angle from the front end portion of the flat portion 24a. A rising portion 24b extending upward and a bent portion 24c formed by being bent in an inclined manner from the tip of the rising portion 24b toward the eaves plate member 23 are formed. Further, the accessory member 24 has a flat portion 24a fastened to the upper end portion of the eaves girder 22 via a bolt or the like. Further, a backing material 26 is filled between the tip portion of the flat portion 24a, the rising portion 24b, and the inclined portion, and mortar is filled between the backing material and the eaves plate member 23.
The nose cover member 25 is formed of a flat lightweight aerated concrete (ALC) panel, similar to the eaves plate member 23, and is provided with one surface facing the eaves end beam 22, and has an upper end portion and a lower end portion. Is attached to the eaves girder 22 via a hardware member k3. Further, the eaves 15 is attached to the other surface of the nose cover member 25.

By arranging each member as described above, the eaves 5 is formed with the eaves back space S surrounded by the eaves girder 2b, the eaves plate member 23, the eaves girder 22 and the nose cover member 25. The back ceiling structure 30 is a structure that closes the eaves back space S from below.
The eaves-behind ceiling structure 30 includes a front girder lower metal piece 36 extending from the eaves girder to the lower end portion of the nose cover member 25, a bracket hardware 31a attached to the lower end portion of the front girder lower metal piece 36, and the bracket hardware 31a. Eaves attachment hardware 32 suspended from the eaves, an outer wall attachment hardware 33 attached to the lower end of the eaves girder 2b and connected to the Z hardware k2 supporting the outer wall 2, and between the eaves attachment hardware 32 and the outer wall attachment hardware 33 And an eaves top member 80 that spans the eaves attachment hardware 32 and the outer wall attachment hardware 33 and is suspended from the eaves assembly 34.

The bracket hardware 31a includes an attachment portion 31b that is attached to the nose cover member 25 via a tapping screw or the like in a state where the bracket hardware 31a is overlapped with the leading digit lower hardware 36, and a horizontal plate portion 31c that extends toward the outer wall of the building. In addition, the eaves attachment hardware 32 is formed by press forming a metal plate, a fastening portion 32b fastened to the horizontal plate portion 31c of the bracket hardware 31a via a bolt or the like, and a tip of the fastening portion 32b. A small edge portion 32c formed by bending from the portion, and a seat portion 32d formed by bending from the lower end portion of the small edge portion 32c.
About each structure of the remaining eaves back ceiling structure 30, since it is the same as that of the said 1st Embodiment, the code | symbol similar to the said 1st Embodiment is attached | subjected and the description is abbreviate | omitted.

Also in the present embodiment, as in the first embodiment, since the fireproof reinforcing body 81a including the fireproof heat insulating layer 82 and the heat shielding layer 83 is provided on the eaves back ceiling board 35, the eaves back ceiling board 35 is provided. The movement of heat to the eaves back space S via the route is suppressed, thereby improving the fire resistance of the eaves back ceiling structure 30 using only the eaves back ceiling plate 35.
Further, this embodiment can be applied to the lower structure d of the overhanging floor of the overhanging veranda D provided on the second floor of the house 1 as shown in FIG. 9 regardless of only the roof structure 1c. In such a configuration, a handrail wall 26 is attached in place of the accessory member 24 and the nose cover member 25. The handrail wall 26 is formed of a flat lightweight aerated concrete (ALC) panel like the eaves plate member 23, the lower end portion is positioned below the eaves end girder 22, and the upper end portion is the second floor outer wall 2. It is attached to the eaves girder 22 via an attachment hardware etc. in the state located in the middle part.

As mentioned above, although embodiment of the eaves back ceiling structure 30 of this invention was explained in full detail, this invention is not limited only to the said embodiment.
For example, the eaves back ceiling structure 30 can also be employed in the ceiling structure of the first floor portion of the house 1 having the first floor as a piloty.

  The configuration of the present invention is as described above, and in order to confirm the effectiveness of the present invention, the inventors of the present invention have a plurality of examples and comparative examples shown below as the eaves ceiling member 80 and the eaves back ceiling board 35. The experiment was conducted using this. In addition, the eaves ceiling member 80 of the said Example contains not only what integrated the eaves back ceiling board 35 and the fireproof reinforcement layer 81 but the structure which mounted the fireproof reinforcement 81a in the eaves back ceiling board 35. FIG.

※（ ）内は、膨張後の厚さを示す。 <Example 1>

* () Indicates the thickness after expansion.

<Example 2>

<Comparative Example 1>

(Test method)
FIG.11 and FIG.12 has shown the structure common to each test body except the presence or absence of the fireproof reinforcement layer 81, and its structure. As shown in the figure, each test body is commonly provided with an eaves-backed ceiling structure 30 excluding the rafter member 12, the joint hardware 13, the nasal cover member 14, and the fireproof reinforcing body 81a of the first embodiment. An eaves top member 80 (eave back ceiling plate 35, fireproof reinforcement 81a, etc.) is provided at a predetermined position of the back ceiling structure 30. In addition, in the comparative example, only the eaves back ceiling board 35 is provided.
The test body is a model obtained by extracting only the part defined by the three rafter members 12 lined up at equal intervals from the eaves installed in the girder direction in the house 1. The eaves protrusion L1 is 550 mm, and the length L2 in the carry direction is 1000 mm. Moreover, the eaves back ceiling board 35 of an Example and the eaves back ceiling board 35 of a comparative example are laying | laying up side by side two sheets of 427 mm in the beam-to-beam direction and 500 mm in the direction of a beam.

In addition, each test body covers all surfaces except the lower surface of the eaves back ceiling plate 35 with a heat-resistant wall W formed by laminating two fiber-mixed calcium silicate plates with a thickness of 25 mm, thereby allowing the eaves back ceiling. Only the lower surface of the plate 35 is exposed. Further, an opening formed at a position where the outer wall placed on the rafter member 12, the heat-resistant wall W to be imitated, and the eaves are joined is covered with a flat standard plate Q.
In addition, thermocouples are respectively charged in the test specimens at positions a, b, and c in FIGS. 11 and 12.
In addition, the said FIG. 11 has shown the test body of Example 2. FIG.
Then, each test specimen is installed in a fireproof test furnace, and then a flame is emitted toward the exposed surface of the eaves back ceiling board 35 of the test specimen to reproduce the time of the fire, and the temperature of each thermocouple due to the flame radiation. Record changes.
And while measuring time until the average temperature of a or b becomes 140 degreeC or more as fireproof time, the log | history of the temperature rise of each thermocouple is observed.
The flame heat setting is in accordance with the standard fire curve defined in ISO834, and the temperature curve is defined by the following equation (1).

The test method corresponds to the predetermined test described above, and corresponds to a fire test approved by the Minister of Land, Infrastructure, Transport and Tourism.
(Test results)
FIG. 13 shows the test results of Example 1, where graph (A) is a standard fire resistance curve, graph (B) is a straight line indicating 140 ° C., graph (C) is an average temperature curve of a and b, and (D). Indicates a temperature curve of c. Moreover, FIG. 14 is a test result of Example 2, and each graph is the same as that of FIG. FIG. 15 shows the test results of Comparative Example 1, and each graph is the same as FIG.
As is apparent from the figure, the fire resistance time of Example 1 and Example 2 is longer than the fire resistance time of Comparative Example 1, so that the configurations of Example 1 and Example 2 are effective in improving the fire resistance performance. It is confirmed. The fireproof time of the comparative example is 35 minutes, while the fireproof time of Example 1 is 52 minutes, and the fireproof time of Example 2 is 77 minutes.
The fireproof time is the time it takes for the average temperature rise of each thermocouple to exceed 140 ° C from the start of combustion (start of temperature measurement), and this provision is the fireproof test approved by the Minister of Land, Infrastructure, Transport and Tourism. It corresponds to.

  In order to confirm the effectiveness of the present invention, the present inventors further conducted experiments using a plurality of examples shown below as the eaves ceiling member 80 and the eaves back ceiling board 35. In addition, the eaves ceiling member 80 of the said Example contains not only what integrated the eaves back ceiling board 35 and the fireproof reinforcement layer 81 but the structure which mounted the fireproof reinforcement 81a in the eaves back ceiling board 35. FIG.

<Example 3>

(Test method)
16 and 17 show the configuration of the test body of Example 3 described above. As shown in the figure, the test body includes the rafter member 12, the joint hardware 13, and the nasal cover member 14 of the first embodiment, and also includes an eaves back ceiling plate 35 and a fireproof reinforcement 81a.
The test body is a model obtained by extracting only the part defined by the five rafter members 12 lined up at equal intervals from the eaves installed in the direction of girder in the house 1. The eaves protrusion L1 is set to 550 mm, and the length L2 in the carry direction is set to 3200 mm. In addition, the eaves back ceiling board 35 is laid with the same four pieces as in the first embodiment. Other configurations are the same as those in the first embodiment.
In addition, thermocouples are charged into the test specimens at positions a, b, c, and d in FIGS. 16 and 17, respectively.
Then, each test specimen is installed in a fireproof test furnace, and then a flame is emitted toward the exposed surface of the eaves back ceiling board 35 of the test specimen to reproduce the time of the fire, and the temperature of each thermocouple due to the flame radiation. Record changes. The reproduction of the fire is the same as in the first embodiment. In addition, since the example 3 is simply changed in size according to the experimental equipment, even if the size is different from the example 1 or the like, it is implemented in the same manner as the example and the comparative example. It is possible to grasp the tendency of the configuration in Example 3.

<Example 4>

(Test method)
About Example 4, since it is the same as the test method of the said Example 1 etc. about structures other than the structure of a fireproof reinforcement body, the description is abbreviate | omitted.

(Test results)
18 and 19 show the test results of Example 3, wherein graph (A) is a standard refractory curve, graph (B) is a straight line indicating 140 ° C., graph (C) is a temperature curve of a ′, graph (D) shows the average temperature curve of b ′, graph (e) shows the temperature curve of c ′, and graph (f) shows the average temperature curve of d ′.
FIG. 20 shows the test results of Example 4. The graph (A) is a standard fire resistance curve, the graph (B) is a straight line indicating 140 ° C., the graph (C) is an average temperature curve of a and b, ) Shows the temperature curve of c.
As is apparent from the figure, the fire resistance time of Example 3 and Example 4 is longer than that of Comparative Example 1, and thus the configurations of Example 3 and Example 4 are effective in improving the fire resistance performance. It is confirmed. The fireproof time of the comparative example is 35 minutes, whereas the fireproof time of Example 3 is 60 minutes or more, and the fireproof time of Example 4 is about 47 minutes.

It is sectional drawing of the house of a dormitory roof provided with the eaves back ceiling structure of 1st Embodiment of this invention. It is sectional drawing of this eaves back ceiling structure. It is sectional drawing of the eaves back ceiling structure of 2nd Embodiment of this invention. It is sectional drawing which shows the procedure which equips a fireproof reinforcement body. FIG. 5 is a cross-sectional view illustrating a procedure for providing a fireproof reinforcement body subsequent to FIG. 4. It is principal part sectional drawing of the eaves back ceiling structure of 3rd Embodiment of this invention. It is principal part sectional drawing of another eaves back ceiling structure. It is principal part sectional drawing of the eaves back ceiling structure explaining the modification of 3rd Embodiment. It is sectional drawing of the house of a flat roof provided with the eaves back ceiling structure of 4th Embodiment of this invention. It is sectional drawing of this eaves back ceiling structure. 3 is a cross-sectional view showing a configuration of a test body of Example 2. FIG. FIG. 11 is a schematic cross-sectional view taken along line AA in FIG. 3 is a graph showing test results of Example 1. 6 is a graph showing test results of Example 2. 6 is a graph showing test results of Comparative Example 1. FIG. 4 is a cross-sectional view showing a configuration of a test body of Example 3. FIG. 4 is a cross-sectional view showing a configuration of a test body of Example 3. 10 is a graph showing test results of Example 3. 10 is a graph showing test results of Example 3. 10 is a graph showing test results of Example 4.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Housing 2 Building body 3 1st floor roof 4 2nd floor roof 5 houses 10 eaves structure 11 Roof board member 12 Rafter member 13 Joint hardware 14 Nasal concealment member 30 Eaves structure 31 L-shaped hardware 32 Eaves installation hardware 33 Outer wall installation hardware 34 Field Edge Assembly 35 Eaves Back Ceiling 51 Field Edge 52 Field Edge Receptor 80 Eave Top Member 81 Fireproof Reinforcement Layer 81a Fireproof Reinforcement Body 82 Fireproof Thermal Insulation Layer 83 Heat Shutdown Layer 84 Heat Absorption Layer S

Claims (15)

In the eaves roof ceiling structure in which an eave roof member having a predetermined fire resistance performance is provided on the back side of the eaves of the building, and an eave back space is formed above the eave roof member,
The eaves top member includes an eaves back ceiling board having a predetermined fire resistance performance, and a fireproof reinforcement layer laminated on the eaves back ceiling board, the fireproof reinforcement layer including a fireproof heat insulation layer, a heat insulation layer, An eaves-ceiling structure characterized by being formed by any one of the heat absorbing layers or by laminating two or all layers.   2. The eaves according to claim 1, wherein the fireproof heat insulating layer is formed of an expanded heat insulating sheet or an expanded heat insulating coating film that expands due to a temperature rise caused by fire and forms a heat insulating layer having a predetermined thickness. Back ceiling structure.   The eaves roof ceiling structure according to claim 1 or 2, wherein the heat shield layer is formed of an aluminum thin film, a zinc iron plate, or a steel plate.   The eaves back ceiling structure according to any one of claims 1 to 3, wherein the endothermic layer is formed using aluminum hydroxide as a main material.   5. The eaves-behind ceiling structure according to claim 4, wherein the endothermic layer is formed by laying a sachet formed by encapsulating aluminum hydroxide powder. In the eaves back ceiling structure in which an eaves back ceiling board having predetermined fire resistance performance is provided on the back side of the eaves of the building, and an eave back space is formed above the eaves back ceiling board,
The eaves-behind ceiling structure is characterized in that the upper surface of the eaves-rear ceiling plate is covered with a fireproof reinforcing body having a heat absorbing layer formed of aluminum hydroxide as a main material.   The eaves-ceiling structure according to claim 6, wherein the endothermic layer is formed by laying a sachet formed by encapsulating aluminum hydroxide powder.   The eaves-reinforcing ceiling structure according to claim 6, wherein the fireproof reinforcing body is provided with the heat absorption layer according to claim 7 and a heat shielding layer mainly composed of aluminum.   The fireproof reinforcement is provided in the eaves space in a state where the heat absorption layer is placed on the upper surface of the eaves back ceiling plate and the heat blocking layer is stacked on the upper surface of the heat absorption layer. The eaves-behind ceiling structure according to claim 8.   A fireproof reinforcement layered on an eaves ceiling ceiling board that forms the eaves ceiling ceiling structure of a building, comprising any one of a fireproof heat insulating layer, a heat shielding layer, and an endothermic layer, or two or all of them A fireproof reinforcement body characterized by being formed by laminating layers.   A fireproof reinforcing body laminated on an eaves ceiling ceiling board forming a roof eaves ceiling structure of a building, comprising a heat absorbing layer mainly composed of aluminum hydroxide.   The fireproof reinforcing body according to claim 11, wherein the endothermic layer is formed by laying a sachet formed by encapsulating aluminum hydroxide powder.   The fireproof reinforcing body according to claim 11 or 12, wherein the heat-absorbing layer and a heat shielding layer made of aluminum are provided.   The fireproof reinforcing body according to claim 13, wherein the endothermic layer is located on the eaves back ceiling board, and the heat blocking layer is located on the endothermic layer. A plurality of eaves-backed ceiling boards with a predetermined fire resistance performance are laid out along the eaves direction of the eaves to form an eaves-back space, and the side edges along the outer wall of the building are the outer walls. A fireproof reinforcement method of the eaves back ceiling structure that is held by the eaves mounting hardware that is held by the mounting eaves and the side edge along the eaves is supported by the eaves,
Remove one of the mounting hardware to release the holding state of one side edge of the eaves back ceiling board,
The upper side of the eaves back ceiling board is exposed by swinging the eaves back ceiling board in the downward direction with the other side edge as the swing axis,
Laying fireproof reinforcement on the upper surface of the eaves back ceiling plate,
After swinging the eaves-back ceiling board in the upward direction around the swing axis, the one attachment metal is attached to make the one side edge of the eaves-back ceiling board hold again. Fireproof reinforcement method for eaves back ceiling structure.

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