Fireproof external wall structure

Abstract

To provide a refractory outer wall structure capable of improving workability at a construction site and easily constructing a refractory outer wall having high quality and hardly causing deflection in an out-of-plane direction by wind pressure or the like in an in-plane direction intermediate part while having a constitution for suppressing internal dew condensation by providing an air layer.SOLUTION: The fireproof external wall structure is constructed by spraying a fireproof coating material 3 on the indoor side of a metal panel 11 to a predetermined thickness, and is provided with an outer metal panel 13 arranged on the outdoor side of the metal panel 11 with an air layer 12 in between, and a plurality of interval holding members 14 for holding the interval between the metal panel 11 and the outer metal panel 13 to an interval corresponding to the air layer 12. A plurality of interval holding members 14 are arranged at an intermediate part in an in-plane direction between opposed surfaces of a metal panel 11 and an outer metal panel 13, and the metal panel 11 and the outer metal panel 13 are integrally connected through the interval holding members 14 to constitute a double metal panel unit 10.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a fire-resistant exterior wall structure constructed by spraying a fire-resistant covering material to a predetermined thickness onto the interior side of a metal panel. [Background technology]

[0002] An example of such a fire-resistant exterior wall structure is one in which, at a construction site, furring strip panels, which serve as the mounting base for the exterior wall surface materials, are attached to multiple pillars arranged at regular intervals along the perimeter of the building, and then a fire-resistant coating material such as rock wool is sprayed around the pillars and on the indoor side of the furring strip panels.Furthermore, the exterior wall surface materials (corrugated iron plates) are attached via hat-shaped joiners installed in the vertical joints between adjacent exterior wall surface materials at a position separated by an air layer from the fire-resistant base material (iron plate) fixed to the surface of the furring strip panels on the outdoor side (see, for example, Patent Document 1), thereby creating an air layer between the fire-resistant base material (iron plate) of the furring strip panels and the exterior wall surface materials (corrugated iron plates) (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6783508 Summary of the Invention [Problem to be solved by the invention]

[0004] In the fire-resistant exterior wall structure described in Patent Document 1, an air layer is provided between the fire-resistant base material (steel plate) of the furring lining panels and the exterior wall surface material (corrugated iron plate), which prevents the fire-resistant base material (steel plate) of the furring lining panels from coming into contact with cold outside air and being cooled in winter, etc. This prevents internal condensation that occurs when moisture from inside the room passes through the rock wool and comes into contact with the back of the fire-resistant base material (steel plate) that has been cooled by outside air, even if rock wool, a fibrous material with low moisture resistance, is used as the fire-resistant covering material.

[0005] However, in the fire-resistant exterior wall structure described in Patent Document 1, the exterior wall facing material is attached to the exterior side of the fire-resistant base material at a position separated by an air gap at the construction site, making it difficult to accurately ensure a gap corresponding to the air gap between the fire-resistant base material and the exterior wall facing material. Therefore, there is room for improvement in terms of workability at the construction site. Furthermore, because the exterior wall facings are attached to the fire-resistant base material via the vertical joints between adjacent exterior wall facings, i.e., hat-shaped joiners provided between the in-plane ends of adjacent exterior wall facings, the in-plane intermediate portions of the exterior wall facings are prone to bending out of the plane. Therefore, there is room for improvement in constructing high-quality fire-resistant exterior walls that are less likely to bend out of the plane due to wind pressure or other factors at the in-plane intermediate portions.

[0006] In view of this situation, the main object of the present invention is to provide a fire-resistant exterior wall structure that can suppress internal condensation by providing an air layer, while improving workability at the construction site, and that can easily construct a high-quality fire-resistant exterior wall that is less likely to deflect in the out-of-plane direction due to wind pressure or the like at intermediate locations in the in-plane direction. [Means for solving the problem]

[0007] The first characteristic configuration of the present invention is a fire-resistant exterior wall structure constructed by spraying a fire-resistant covering material to a predetermined thickness on the indoor side of a metal panel, an outer metal panel arranged on the outdoor side of the metal panel with an air layer between them; and a plurality of spacing members that maintain a distance between the metal panel and the outer metal panel at a distance corresponding to the air layer; a plurality of the spacing members are disposed at intermediate positions in an in-plane direction between the opposing surfaces of the metal panel and the outer metal panel; The metal panel and the outer metal panel are configured as a double metal panel unit that is integrally connected via the spacing member.

[0008] According to this configuration, in a factory or work yard near a construction site, multiple spacing members are placed in the in-plane intermediate position between the opposing surfaces of the metal panel and the outer metal panel to maintain the distance between the metal panel and the outer metal panel at a distance corresponding to the air layer, and the metal panel and the outer metal panel are connected together via the spacing members.This makes it possible to pre-manufacture with high precision a double metal panel unit in which the distance corresponding to the air layer between the metal panel and the outer metal panel is properly maintained and in which deflection in the out-of-plane direction due to wind pressure, etc. at the in-plane intermediate position is suppressed.

[0009] The double metal panel unit thus manufactured in advance is then transported to the construction site and attached to wall underlayment materials such as vertical furring strips at the construction site. After that, a fire-resistant coating material such as rock wool or cement slurry is sprayed onto the interior side of the metal panel in a specified thickness, thereby easily constructing a fire-resistant exterior wall in which the heat transfer coefficient is reduced by the air layer (insulating layer) between the metal panels, effectively suppressing internal condensation.

[0010] Therefore, it is possible to provide a fire-resistant exterior wall structure that has an air layer that can effectively suppress internal condensation, while improving workability at the construction site and making it easy to construct a high-quality fire-resistant exterior wall that is less likely to deflect in the out-of-plane direction due to wind pressure at the middle of the in-plane direction.

[0011] A second characteristic feature of the present invention is that in the double metal panel unit, the bolt joints that join the metal panels and the spacing members together with bolts are treated to be airtight.

[0012] According to this configuration, when manufacturing a double metal panel unit in a factory or a work yard near a construction site, the bolt joint between the metal panel and the spacing member on the indoor side of the double metal panel unit can be easily and reliably treated to be airtight.

[0013] Therefore, it is easy to construct a highly airtight fire-resistant exterior wall that can prevent the inconvenience of water vapor and the like from the indoor side flowing into the air layer between the metal panel and the outer metal panel through the bolt joint between the metal panel located on the indoor side of the double metal panel unit and the spacing member, causing condensation.

[0014] A third characteristic feature of the present invention is that an airtight treatment is applied to the boundary between the metal panel and the outer metal panel in the double metal panel unit.

[0015] According to this configuration, when manufacturing a double metal panel unit in a factory or a work yard near a construction site, airtight treatment can be easily and reliably performed on the boundary between the metal panel and the outer metal panel in the double metal panel unit.

[0016] Therefore, it is easy to construct a highly airtight fire-resistant exterior wall that can prevent the inconvenience of indoor and outdoor water vapor and the like from flowing into the air layer between the metal panel and the outer metal panel at the boundary between the metal panel and the outer metal panel in the double metal panel unit and causing condensation.

[0017] In a fourth characteristic configuration of the present invention, the metal panel and the outer metal panel each have a peripheral surface portion bent from an outer peripheral edge toward the indoor side in an out-of-plane direction to form an outer peripheral surface, and a back surface portion bent from an indoor side edge of the peripheral surface portion toward an in-plane direction and extending along the in-plane direction, such that the back surface portion of the outer metal panel is adjacent to the outer peripheral side of the back surface portion of the metal panel along the in-plane direction, As an airtight treatment at the boundary portion, an airtight tape is attached over the entire periphery of the back surface portion of the metal panel and the back surface portion of the outer metal panel.

[0018] According to this configuration, the aforementioned peripheral portion and back portion are formed by folding on each of the metal panel and the outer metal panel, thereby enabling each of the metal panel and the outer metal panel to be configured to ensure high rigidity.

[0019] Furthermore, by using the entire periphery of each back surface of the metal panel and the outer metal panel as the adhesive surface for the airtight tape, which ensures high rigidity for each, the airtight tape can be easily applied in a manner that continuously blocks the gap between the back surface of the metal panel and the back surface of the outer metal panel, which is the boundary between the metal panel and the outer metal panel, along the entire periphery of those back surfaces.

[0020] Therefore, it is possible to rationally perform a highly airtight seal treatment on the boundary between the metal panel and the outer metal panel. [Brief explanation of the drawings]

[0021] [Figure 1] Horizontal cross section of the fireproof exterior wall and enlarged horizontal cross section of the main part [Figure 2] Vertical cross section of the fireproof exterior wall and enlarged vertical cross section of the main part [Figure 3] (a) is a horizontal cross-sectional view showing the disassembled state of the double metal panel unit (fire-resistant exterior wall), and (b) is a horizontal cross-sectional view showing the double metal panel unit (fire-resistant exterior wall) and an enlarged horizontal cross-sectional view of the main part. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, an example of an embodiment for carrying out a fire-resistant exterior wall structure according to the present invention will be described with reference to the drawings.

[0023] As shown in Figures 1 and 2, the fire-resistant exterior wall structure exemplified in this embodiment can be constructed by attaching multiple fire-resistant exterior wall bodies 10 to a main structural element (not shown), such as a building's columns, via multiple vertical furring strips 1 and horizontal furring strips 2 as wall base materials, and then spraying a predetermined thickness of rock wool 3, an example of a fire-resistant coating material, onto the indoor side of the fire-resistant exterior wall bodies 10, including the indoor side of the vertical furring strips 1 and horizontal furring strips 2. Each of the vertical and horizontal joints between adjacent fire-resistant exterior wall bodies 10 is sealed with sealant 4 to make the joints airtight. Lightweight lip channel steel is used for the vertical furring strips 1 and horizontal furring strips 2.

[0024] Note that materials other than lip channel steel, such as channel steel without a lip or H-shaped steel, can be used for the vertical furring strips 1 and horizontal furring strips 2. Also, materials other than rock wool 3, such as mortar, can be used for the fire-resistant covering material.

[0025] The fire-resistant exterior wall body 10 is provided with a metal panel (hereinafter referred to as the inner metal panel) 11 arranged on the indoor side thereof, an outer metal panel 13 arranged on the outdoor side of the inner metal panel 11 with an air layer 12 between them, and a plurality of spacing members 14, 15 that maintain the distance between the inner metal panel 11 and the outer metal panel 13 at a distance corresponding to the air layer 12. The aforementioned rock wool 3 is sprayed to a predetermined thickness onto the indoor side of the inner metal panel 11 of the fire-resistant exterior wall body 10.

[0026] In other words, the fire-resistant exterior wall structure exemplified in this embodiment has multiple fire-resistant exterior wall bodies 10 attached to the main structure via multiple vertical furring strips 1 and horizontal furring strips 2, each of which has a double metal panel structure in which a highly insulating air layer 12 is secured between the inner metal panel 11 on the indoor side and the outer metal panel 13 on the outdoor side, thereby preventing the inner metal panel 11 on the indoor side from coming into contact with the cold outside air and being cooled, for example in winter.

[0027] This makes it possible to prevent internal condensation, which occurs when moisture from the indoor side passes through the rock wool 3 and comes into contact with the back of the indoor-side inner metal panel 11, which is cooled by the outside air, even when rock wool 3, a fibrous material with low moisture resistance, is used as the fire-resistant covering material, as described above.

[0028] A relatively inexpensive steel panel is used for the inner metal panel 11, and an aluminum panel with a highly aesthetic appearance is used for the outer metal panel 13. The spacing members 14, 15 are made of steel material that has been bent to have a hat-shaped cross section.

[0029] Note that materials other than steel panels, such as aluminum panels, can be used for the inner metal panel 11, and materials other than aluminum panels, such as steel panels, can be used for the outer metal panel 13. Furthermore, materials other than steel, such as aluminum panels, can be used for the spacing members 14, 15.

[0030] 1 to 3, the inner metal panel 11 and the outer metal panel 13 each include a front portion 11A, 13A formed into a rectangular flat surface, peripheral surface portions 11B, 13B bent from the outer peripheral edge of the front portion 11A, 13A toward the indoor side in an out-of-plane direction to form an outer peripheral surface, and back portion 11C, 13C bent from the indoor-side edge of the peripheral surface portion 11B, 13B toward the in-plane direction and extending along the in-plane direction. Thus, the inner metal panel 11 and the outer metal panel 13 each include the peripheral surface portions 11B, 13B and the back portion 11C, 13C bent to form the inner metal panel 11 and the outer metal panel 13, respectively, so that the inner metal panel 11 and the outer metal panel 13 each have high rigidity.

[0031] As shown in FIGS. 1 to 3, among the multiple spacing members 14, 15, spacing member 14 is a vertically elongated spacing member (see FIGS. 1 and 3) used in a vertical position extending in the vertical direction of fire-resistant exterior wall body 10, and spacing member 15 is a horizontally elongated spacing member (see FIG. 2) used in a horizontal position extending in the horizontal direction of fire-resistant exterior wall body 10. As shown in FIGS. 1 and 3, vertically elongated spacing member 14 is arranged at a predetermined interval in the horizontal direction of fire-resistant exterior wall body 10 in an intermediate position in the in-plane direction between the opposing surfaces of inner metal panel 11 and outer metal panel 13. As shown in FIG. 2, horizontally elongated spacing member 15 is arranged at a predetermined interval in the vertical direction of fire-resistant exterior wall body 10 in an intermediate position in the in-plane direction between the opposing surfaces of inner metal panel 11 and outer metal panel 13.

[0032] 3, each of the vertically elongated spacing members 14 and the horizontally elongated spacing members 15 is configured so that central portions 14A, 15A of the hat-shaped cross section are joined to the inner metal panel 11 with bolts 5, and both end portions 14B, 15B of the hat-shaped cross section are welded to the outer metal panel 13. Therefore, central portions 14A, 15A of the hat-shaped cross section are provided with a plurality of through holes 14a, 15a and weld nuts 14b, 15b at predetermined intervals in the extension direction of spacing members 14, 15, which enable bolt joining to inner metal panel 11.

[0033] The front portion 11A of the inner metal panel 11 has a plurality of through holes 11a arranged at predetermined intervals in the horizontal and vertical directions of the fire-resistant exterior wall body 10, which enable bolt connection to the spacing members 14, 15. The vertical spacing members 14 and the horizontal spacing members 15 are welded to the back surface of the front portion 11A of the outer metal panel 13, each arranged at predetermined intervals in the horizontal or vertical direction of the fire-resistant exterior wall body 10.

[0034] 1 to 3, the peripheral surfaces 11B, 13B of the inner metal panel 11 and the outer metal panel 13 are each formed of an upper surface 11Ba, 13Ba, a lower surface 11Bb, 13Bb, a left side surface 11Bc, 13Bc, and a right side surface 11Bd, 13Bd. The lower surface 13Bb of the outer metal panel 13 is provided at both left and right ends on the outdoor side with through-holes 13a that allow outside air to be introduced into the air layer 12 between the inner metal panel 11 and the outer metal panel 13 to reduce the humidity of the air layer 12 and allow condensation to be discharged to the outside if condensation occurs in the air layer 12 (see FIG. 2).

[0035] Each of the rear portions 11C, 13C of the inner metal panel 11 and the outer metal panel 13 is formed of an upper rear portion 11Ca, 13Ca, a lower rear portion 11Cb, 13Cb, a left rear portion 11Cc, 13Cc, and a right rear portion 11Cd, 13Cd. In the inner metal panel 11, each of the upper rear portion 11Ca, the lower rear portion 11Cb, the left rear portion 11Cc, and the right rear portion 11Cd is a folded portion that is folded back toward the center of the panel in the in-plane direction.

[0036] On the other hand, the upper back portion 13Ca, the left back portion 13Cc, and the right back portion 13Cd of the outer metal panel 13 form flange portions that are folded outward in the in-plane direction of the panel, and only the lower back portion 13Cb forms a folded portion that is folded back toward the center in the in-plane direction. The upper back portion 13Ca, the left back portion 13Cc, and the right back portion 13Cd of the outer metal panel 13 are each used as a fixing portion that is fixed to the vertical furring strips 1 or the horizontal furring strips 2 with screws 6. The lower back portion 13Cb of the outer metal panel 13 also functions as a water-repellent portion that prevents condensation generated in the air layer 12 and rainwater blown in through the through holes 13a in the lower surface portion 13Bb from penetrating into the interior of the room.

[0037] Incidentally, as shown in Figure 1, the left rear portion 13Cc and the right rear portion 13Cd of the outer metal panel 13 are fastened together to the vertical furring strip 1 with screws 6, with the left rear portion 13Cc and the right rear portion 13Cd of adjacent outer metal panels 13 overlapping each other front to back.

[0038] As shown in Figure 3, the fire-resistant exterior wall body 10 is constructed as a double metal panel unit in which an inner metal panel 11 and an outer metal panel 13 are integrally connected via the aforementioned multiple vertical spacing members 14 and horizontal spacing members 15.

[0039] With this configuration, for example, in a work yard near a factory or construction site, a plurality of vertical spacing retaining members 14 and horizontal spacing retaining members 15 can be placed in the in-plane intermediate position between the opposing surfaces of the inner metal panel 11 and the outer metal panel 13 to maintain the distance between them at a distance corresponding to the air layer 12, and the inner metal panel 11 and the outer metal panel 13 can be integrally connected via the vertical spacing retaining members 14 and horizontal spacing retaining members 15.This makes it possible to pre-fabricate a double metal panel unit as a fire-resistant exterior wall 10 with high precision in advance, in a state in which the distance corresponding to the air layer 12 is properly maintained between the inner metal panel 11 and the outer metal panel 13, and in which deflection in the out-of-plane direction due to wind pressure, etc. at the in-plane intermediate position is suppressed.

[0040] As shown in Figures 1 to 3, in the double metal panel unit (fire-resistant exterior wall body) 10, a gap 7 is secured between the peripheral portion 11B of the inner metal panel 11 and the peripheral portion 13B of the outer metal panel 13, which prevents heat conduction between the inner metal panel 11 and the outer metal panel 13 and absorbs the difference in thermal expansion coefficient between the inner metal panel 11 and the outer metal panel 13.

[0041] As shown in Figure 3, in the double metal panel unit 10, the bolt joints 16 that bolt the inner metal panel 11 to the vertically elongated spacing members 14 or the horizontally elongated spacing members 15 are treated to be airtight. In the airtight treatment at the bolt joints 16, rubber washers 17 are interposed between the back surface of the front portion 11A of the inner metal panel 11 and the heads of the bolts 5, thereby increasing the airtightness at the bolt joints 16.

[0042] With this configuration, when double metal panel unit 10 is fabricated in a factory, a work yard near a construction site, or the like, airtight treatment can be easily and reliably performed on bolt joints 16 between inner metal panel 11 and vertical spacing members 14 or horizontal spacing members 15 on the indoor side of double metal panel unit 10. As a result, a highly airtight double metal panel unit 10 can be easily constructed, which can prevent the inconvenience of water vapor and the like from the indoor side flowing through bolt joints 16 between inner metal panel 11 and vertical spacing members 14 or horizontal spacing members 15 on the indoor side of double metal panel unit 10 into air layer 12 between inner metal panel 11 and outer metal panel 13, causing condensation.

[0043] As shown in FIGS. 1 and 2 , in the double metal panel unit 10, an airtight treatment is also performed on the boundary between the inner metal panel 11 and the outer metal panel 13. More specifically, the airtight treatment at this boundary is performed by forming the inner metal panel 11 and the outer metal panel 13 such that the back surface 13C of the outer metal panel 13 is adjacent to the outer periphery of the back surface 11C of the inner metal panel 11 along the in-plane direction. This creates a gap between the back surface 11C of the inner metal panel 11 and the back surface 13C of the outer metal panel 13 at the boundary between the inner metal panel 11 and the outer metal panel 13 in the double metal panel unit 10. The airtight treatment at this boundary is performed by attaching an airtight tape 18 that spans the back surface 11C of the adjacent inner metal panel 11 and the back surface 13C of the outer metal panel 13 around the entire periphery of the back surfaces 11C, 13C. This enhances the airtightness at the boundary between the inner metal panel 11 and the outer metal panel 13.

[0044] With this configuration, when double metal panel unit 10 is fabricated in a factory, a work yard near a construction site, or the like, airtight treatment can be easily and reliably performed on the boundary between inner metal panel 11 and outer metal panel 13 of double metal panel unit 10. As a result, a highly airtight double metal panel unit 10 can be easily constructed, which can prevent the inconvenience of indoor and outdoor water vapor and the like from flowing into air layer 12 between inner metal panel 11 and outer metal panel 13 through the boundary between inner metal panel 11 and outer metal panel 13 of double metal panel unit 10 and causing condensation.

[0045] Furthermore, when performing airtight treatment on such a boundary area, the entire periphery of each of the back surfaces 11C, 13C, which are formed by bending the inner metal panel 11 and the outer metal panel 13 to ensure high rigidity, can be used as the application surface for the airtight tape 18. This makes it possible to easily apply the airtight tape 18 in a manner that continuously closes the gap between the back surface 11C of the inner metal panel 11 and the back surface 13C of the outer metal panel 13, which constitutes the boundary area between the inner metal panel 11 and the outer metal panel 13, along the entire periphery of those back surfaces 11C, 13C. As a result, a highly airtight treatment can be performed rationally on the boundary area between the inner metal panel 11 and the outer metal panel 13.

[0046] Then, as described above, the highly airtight double metal panel unit 10, which has been fabricated in advance in a factory or a work yard near the construction site, is transported to the construction site as a fire-resistant exterior wall body 10 by lifting it with a lifting machine such as a crane, and at the construction site, it is attached to a main structure such as a pillar via multiple vertical furring strips 1 and horizontal furring strips 2.After that, by spraying rock wool 3 to a predetermined thickness onto the indoor side of the inner metal panel 11, etc., a fire-resistant exterior wall W can be easily constructed in which the heat transfer coefficient is reduced in the air layer (insulating layer) 12 between the inner metal panel 11 and the outer metal panel 13, effectively suppressing internal condensation.

[0047] Therefore, the fire-resistant exterior wall structure exemplified in this embodiment has an air layer 12 that can effectively suppress internal condensation, while improving workability at the construction site and making it easy to construct a high-quality fire-resistant exterior wall W that is less likely to deflect in the out-of-plane direction due to wind pressure at the middle of the in-plane direction.

[0048] [Another embodiment] Another embodiment of the present invention will now be described. The configurations of the other embodiments described below are not limited to being applied alone, but can also be applied in combination with the configurations of the above-described embodiment or other other embodiments.

[0049] (1) In the above embodiment, the indoor inner metal panel (metal panel) 11 is exemplified as having the front portion 11A, peripheral portion 11B, and back portion 11C described above, but this is not limited thereto, and for example, it may be a panel having the front portion 11A and peripheral portion 11B but not the back portion 11C.

[0050] (2) In the above embodiment, the indoor-side inner metal panel (metal panel) 11 is exemplified as one in which the upper back portion 11Ca, the lower back portion 11Cb, the left back portion 11Cc, and the right back portion 11Cd that form the aforementioned back portion 11C are each formed as a folded portion that is folded back toward the center of the panel in the in-plane direction. However, this is not limited to this, and for example, at least one of the upper back portion 11Ca, the lower back portion 11Cb, the left back portion 11Cc, and the right back portion 11Cd may be formed as a flange portion that is folded out toward the outside of the panel in the in-plane direction.

[0051] (3) In the above embodiment, the outdoor outer metal panel 13 is exemplified as being formed so that the upper back portion 13Ca, the left back portion 13Cc, and the right back portion 13Cd of the aforementioned back portion 13C become flange portions that are folded out toward the outside of the panel in the in-plane direction, and only the lower back portion 11Cb becomes a folded portion that is folded back toward the center in the in-plane direction. However, this is not limited to this, and for example, the upper back portion 13Ca, the lower back portion 11Cb, the left back portion 13Cc, and the right back portion 13Cd may all be formed to become flange portions, or at least one of the upper back portion 13Ca, the left back portion 13Cc, and the right back portion 13Cd may be formed to become a folded portion together with the lower back portion 11Cb.

[0052] (4) In the above embodiment, the multiple spacing members connecting the indoor inner metal panel (metal panel) 11 and the outdoor outer metal panel 13 are exemplified as being provided with vertical spacing members 14 and horizontal spacing members 15, but this is not limited thereto, and for example, the panel may be provided with only one of the vertical spacing members 14 and the horizontal spacing members 15. [Explanation of symbols]

[0053] 3. Rock wool (fireproof coating material) 10 Double Metal Panel Unit 11 Inner metal panel (metal panel) 11B Peripheral part 11C Back part 12 Air Layer 13 outer metal panel 13B Peripheral part 13C Back part 14 Vertical spacing member (spacing member) 15 Horizontal spacing member (spacing member) 16 Bolted joints 18 Airtight Tape

Claims

1. A fire-resistant exterior wall structure constructed by spraying a fire-resistant coating material to a predetermined thickness on the indoor side of a metal panel, an outer metal panel arranged on the outdoor side of the metal panel with an air layer between them; and a plurality of spacing members that maintain a distance between the metal panel and the outer metal panel at a distance corresponding to the air layer; a plurality of the spacing members are disposed at intermediate positions in an in-plane direction between the opposing surfaces of the metal panel and the outer metal panel; A fire-resistant exterior wall structure in which the metal panel and the outer metal panel are configured as a double metal panel unit integrally connected via the spacing member.

2. 2. The fire-resistant exterior wall structure according to claim 1, wherein the double metal panel unit has bolt joints that connect the metal panels and the spacing members with the bolts, the bolt joints being airtightly treated.

3. 3. The fire-resistant exterior wall structure according to claim 1, wherein an airtight treatment is applied to a boundary between the metal panel and the outer metal panel in the double metal panel unit.

4. The metal panel and the outer metal panel each have a peripheral surface portion bent from their outer peripheral edge toward the indoor side in an out-of-plane direction to form an outer peripheral surface, and a back surface portion bent from the indoor side edge of the peripheral surface portion toward the in-plane direction and extending along the in-plane direction, such that the back surface portion of the outer metal panel is adjacent to the outer peripheral side of the back surface portion of the metal panel along the in-plane direction, 4. The fire-resistant exterior wall structure according to claim 3, wherein the airtight treatment at the boundary portion is performed by attaching an airtight tape extending from the back portion of the metal panel to the back portion of the outer metal panel around the entire periphery of the back portion.

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