JP2019206829A - Ceiling board fall prevention structure and ceiling board fall prevention method - Google Patents

Abstract

To provide a ceiling board fall prevention structure which can be constructed from a ceiling rear side with respect to an existing suspended ceiling, which can reduce occurrence of cracks in the ceiling board, and which can reduce fall of the ceiling board even in the case where the cracks occur in the ceiling board, and a ceiling board fall prevention method.SOLUTION: In a ceiling board fall prevention structure in a suspended ceiling structure in which a ceiling board 27 is suspended and held, on the surface which becomes a ceiling rear side of the ceiling board 27, a surface material 11 in which a rope body 12 is embedded or joined is surface-joined.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a ceiling plate fall prevention structure and a ceiling plate fall prevention method for reducing the fall of a ceiling plate on a suspended ceiling.

For example, a method of hanging a ceiling board from a ceiling slab is widely used in an RC structure building or the like.
In the conventional construction method, a field edge receiver is attached to a suspension bolt suspended from a ceiling slab via a hanger, and a field edge is attached to the field edge receiver by a member such as a clip. And a suspended ceiling is comprised because a ceiling board is attached with a screwing etc. with respect to a field edge.
For such suspended ceilings of conventional construction methods, there is a problem that the ceiling plate falls when a large earthquake occurs, and there is a demand for earthquake resistance measures in existing buildings.
With respect to such a problem, Patent Documents 1 to 5 disclose conventional techniques relating to seismic reinforcement (prevention of fall) of an existing suspended ceiling.

Japanese Utility Model Publication No. 04-110822 JP 2012-012912 A Japanese Patent Laying-Open No. 2015-063853 Japanese Patent Laying-Open No. 2015-183457 JP 2017-014819 A

In the suspended ceiling of the conventional construction method, a gypsum board or the like is often used as a ceiling board. Gypsum board has a side that is easily cracked when stress is applied or a shock is applied by a large shaking at the time of an earthquake, which may cause the ceiling board to fall. If a crack occurs even at one place, the crack spreads from there, and as a result, the ceiling plate may fall in a large range.
Accordingly, a countermeasure is required to reduce the fall even when the ceiling board is cracked or cracked. However, in the techniques disclosed in Patent Documents 2 and 5, the joint portion of the field edge receiver and the hanger is bonded. Therefore, a countermeasure for reducing the fall of the ceiling panel is not made on the ceiling panel.
Moreover, since the techniques disclosed in Patent Documents 3 and 4 require construction from the room side, there is a problem that the room cannot be used during the construction period.
In the technique disclosed in Patent Document 1, construction on the back side of the ceiling is possible, and a countermeasure is taken on the surface of the ceiling plate. However, the technique of Patent Document 1 is a technique for preventing the ceiling plate from falling off the flange of the field edge when the ceiling panel is placed on the field edge flange. The situation where it breaks is not taken into consideration. Therefore, it cannot be said that it is sufficient as a measure for reducing the fall even when the ceiling panel is cracked or broken.

  In view of the above-mentioned points, the present invention can be applied to the existing suspended ceiling from the back side of the ceiling, reduces the occurrence of cracks in the ceiling panel, and falls even when the ceiling panel is cracked. An object of the present invention is to provide a ceiling plate fall prevention structure and a ceiling plate fall prevention method capable of taking measures to reduce the ceiling plate.

(Configuration 1)
A ceiling plate fall prevention structure in a suspended ceiling structure in which a ceiling plate is suspended and held, and a surface material in which a cable body is embedded or joined to a surface which becomes a ceiling back side of the ceiling plate, A ceiling plate fall prevention structure characterized by surface bonding.

(Configuration 2)
The ceiling board fall prevention structure according to Configuration 1, wherein the cable body is fastened to a frame.

(Configuration 3)
A fall prevention tool for reducing the fall of the face material, which is fastened or latched to any one of a field edge, a field edge receiver, a clip, a hanger, and a hanging bolt, and a part of the face material is The ceiling plate fall prevention structure according to Configuration 1 or 2, further comprising a fall prevention device embedded or joined.

(Configuration 4)
A fall prevention tool for reducing the fall of the face material, which is fastened to the housing directly or via another member, and the fall is partially embedded or joined to the face material The ceiling board fall prevention structure according to Configuration 1 or 2, further comprising a prevention tool.

(Configuration 5)
The ceiling plate fall prevention structure according to Configuration 3 or 4, wherein the ceiling plate fall prevention structure includes a connection member that connects the fall prevention devices to each other and is embedded in or joined to the face material.

(Configuration 6)
6. The ceiling board fall prevention structure according to any one of configurations 1 to 5, wherein the face material is formed of a plurality of layers, and the cable body is disposed between the layers of the face material.

(Configuration 7)
7. The ceiling board fall prevention structure according to any one of configurations 1 to 6, wherein the cable bodies are arranged substantially parallel to a field edge.

(Configuration 8)
The structure according to any one of claims 1 to 7, further comprising: a tubular body embedded or joined to the face material, wherein the cord is disposed inside the tubular body. Ceiling board fall prevention structure.

(Configuration 9)
A ceiling plate fall prevention method in a suspended ceiling structure in which a ceiling plate is suspended and held, and a surface material in which a cable body is embedded or joined to a surface which becomes a ceiling back side of the ceiling plate is surface bonded A method of preventing a ceiling board from falling.

(Configuration 10)
The ceiling board falling prevention method according to claim 9, further comprising a step of fastening the cable body to the housing.

(Configuration 11)
The step of surface bonding the face material includes the step of surface bonding the first sheet to a surface on the ceiling back side of the ceiling plate, the step of arranging the cable body on the top of the first sheet, and the cable The method according to claim 9 or 10, further comprising the step of surface-bonding the second sheet to the upper part of the first sheet on which the body is arranged.

(Configuration 12)
The step of surface-bonding the face materials includes the step of forming a first resin layer by applying a fluid resin material to a surface of the ceiling plate that is to be a ceiling back side, and an upper portion of the first resin layer. Disposing the cable body, and applying a fluid resin material to the upper part of the first resin layer on which the cable body is disposed to form a second resin layer. The ceiling board fall prevention method of the structure 9 or 10 characterized by the above-mentioned.

(Configuration 13)
Fastening or latching a fall prevention tool for reducing the fall of the face material to any one of a field edge, a field edge receiver, a clip, a hanger, and a suspension bolt; and the fall prevention tool on the face material And a step of embedding or joining a part of the ceiling plate fall prevention method according to any one of the configurations 9 to 12.

(Configuration 14)
Fastening the fall prevention tool for reducing the fall of the face material directly to the housing or via another member; and embedding or joining a part of the fall prevention tool to the face material; The ceiling board fall prevention method according to any one of Configurations 9 to 12, further comprising:

  According to the ceiling plate fall prevention structure and the ceiling plate fall prevention method of the present invention, it is possible to perform construction from the ceiling back side with respect to an existing suspended ceiling, reduce the occurrence of cracks in the ceiling plate, and Even if it breaks, the fall can be reduced.

The perspective view which shows the outline of the ceiling-plate fall prevention structure of embodiment which concerns on this invention. The figure which shows the outline of the ceiling board fall prevention structure of embodiment in cross section The figure explaining the construction procedure of the ceiling board fall prevention structure of an embodiment The figure which shows the outline of another example of a ceiling board fall prevention structure in cross section The figure which shows the outline of another example of the ceiling board fall prevention structure in cross section Figure showing an example of fall prevention tool The figure which shows another example of the fall prevention tool

  Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. In addition, the following embodiment is one form at the time of actualizing this invention, Comprising: This invention is not limited within the range.

<Embodiment 1>
FIG. 1 is a perspective view schematically showing a ceiling plate fall prevention structure of Embodiment 1 according to the present invention, and FIG. 2 is a conceptual cross-sectional view when viewed along line AA in FIG. It is.
The ceiling board fall prevention structure of this embodiment is for earthquake-proof reinforcement (fall prevention) with respect to the suspended ceiling of the existing building. The suspended ceiling in the conventional construction method is generally held by a field hanger 22 by a hanger 25 that is screwed to a suspension bolt 21 suspended from a ceiling slab (or upper floor slab). On the other hand, the field edge 23 (field edge 23s and field edge 23w) is attached by the clip 24 (clip 24s and clip 24w). The field edge 23 is attached in a direction orthogonal to the field edge receiver 22, thereby forming a lattice-like ceiling base material. FIG. 1 shows a single field edge 23s and a double field edge 23w, and a clip 24s and a clip 24w corresponding to each. And the ceiling board 27 comprised with a gypsum board etc. is attached to the field edge 23 by screwing etc., and the suspended ceiling is comprised.
As an application target of the ceiling plate fall prevention structure of the present embodiment, a specific ceiling is particularly mentioned. A specific ceiling is a ceiling that may fall off due to vibration during an earthquake in the Ministry of Land, Infrastructure, Transport and Tourism Notification No. 771 in 2013. The height from the floor is higher than 6 m and is projected horizontally. The area is larger than 200 m ² and the mass per unit area is larger than 2 kg / m ² .

As shown in FIGS. 1 and 2, the basic structure of the ceiling board fall prevention structure of the present embodiment is that the cable body 12 is embedded between the field edges 23 on the surface of the ceiling board 27 that is on the back side of the ceiling. The face material 11 is joined to the ceiling plate 27 by surface bonding. In FIG. 1, it is assumed that the face material 11 in which the cable bodies 12 are embedded is joined only in two rows near the center.
The face material 11 includes a first sheet 111, a second sheet 112, and a cable body 12 embedded between the first sheet 111 and the second sheet 112.
A 1st sheet | seat is a resin-made sheet | seat material, and the contact bonding layer was formed in both surfaces. The second sheet is also a resin sheet material like the first sheet, but the second sheet has an adhesive layer formed only on the lower surface.
The cable body 12 is made of a stainless steel rope (or a stainless steel rope whose surface is coated with a resin). The cable body 12 is basically disposed so as to be substantially parallel to the field edge 23, and both ends thereof are fastened to a frame (wall, column, beam, etc.).

As shown in FIG. 2, the face material 11 is hooked to the field edge 23 by the fall prevention tool 13.
FIG. 6A is a perspective view of the fall prevention tool 13. The fall prevention tool 13 is a metal fitting for reducing the fall of the face material 11, and is formed on both sides of the hook portion 131 having a U-shaped cross section that is hooked to the field edge 23 and the hook portion 131. Flange portion 132 to be provided.
As shown in FIG. 2, the fall prevention device 13 has a hook portion 131 hooked to the field edge 23 and a flange portion 132 embedded in the face material 11 (the first sheet 111 and the second sheet 13). Used between embedded sheets 112). Thereby, the fall of the face material 11 is further reduced, that is, the fall of the ceiling plate 27 bonded to the face material 11 is further reduced.

Next, with reference to FIG. 3, the construction procedure of the ceiling board fall prevention structure of the present embodiment will be described.
Step 1
First, the upper surface (surface on the back side of the ceiling) of the ceiling plate 27 is cleaned (brushing, polishing cloth hanging, etc.).
Procedure 2 (Fig. 3 (a))
Next, the first sheet 111 is laid along the longitudinal direction between the field edges 23. That is, the first sheet 111 is surface-bonded to the surface of the ceiling plate 27 that is the back side of the ceiling. In the present embodiment, the first sheet 111 is pre-cut with a predetermined width in advance, and has an adhesive layer formed on both sides and a protective sheet for protecting the adhesive layer. use. The “predetermined width” is a width based on 227 mm, 303 mm, 364 mm, or the like, which is a general interval between the field edges 23. It should be noted that instead of using a pre-cut one, it may be one that performs a cutting operation that matches the size at the site. Moreover, the 1st sheet | seat 111 does not have an adhesive layer and you may apply | coat an adhesive agent on the spot.
Procedure 3 (Fig. 3 (b))
Next, the cable body 12 and the fall prevention tool 13 are installed. The cable body 12 has a length that allows both ends of the cable body 12 to reach the housing (wall, column, beam, etc.) and is installed on the first sheet 111, and has both ends of the cable body 12 (wall, column, beam, etc.). ). Various fastening methods may be used to fasten the cable body 12 and the frame. For example, eyebolts are placed on a concrete wall surface, and Japanese Patent No. 6009611, Japanese Patent No. 6185688, Japanese Patent Application No. 2017-9121, Japanese Patent Application No. 2017. For example, the cable body 12 whose end has been processed using a wedge clamp or the like in 198255 or the like is fastened through a shackle. Instead of the eyebolts, anchor bolts may be placed on a concrete wall or the like, a hardware (attachment fitting) may be attached to the anchor bolts with nuts, and the end-processed cable body 12 may be fastened thereto.
The fastening work of the cable body 12 to the housing may be performed after the procedure 4. However, since the tension can be applied to the cable body 12 by fastening with the housing, the work is performed earlier than the procedure 4. The cable body 12 can be arranged in the face material 11 in a linear state. In some cases, the cable body 12 may not be linearly arranged depending on the condition of the ceiling. However, even in this case, the cable body 12 is retracted so that the cable body 12 does not meander (there is no extra length to meander). Thus, it is preferable to arrange the cord 12.
The fall prevention tool 13 is installed so that the hook 131 is hooked to the field edge 23.
Procedure 4 (Fig. 3 (c))
Finally, the second sheet 112 is laid so as to cover the cable body 12 and the fall prevention tool 13. In the present embodiment, like the first sheet 111, the second sheet 112 is pre-cut with a predetermined width in advance, and has an adhesive layer formed on one side and protection for protecting the adhesive layer. Use a sheet provided. In addition, the point which does not have an adhesive layer and the 2nd sheet | seat 112 apply | coats an adhesive agent on the site | part may perform the cutting operation | work which matched the size on the site | part. This is the same as the first sheet 111.
After a predetermined drying time, the construction state is checked and the work is finished.

As described above, according to the ceiling plate fall prevention structure (or ceiling plate fall prevention method) of the present embodiment, it is possible to construct an existing suspended ceiling only from the back side of the ceiling. It can be used.
In addition, since the face material in which the cable body is embedded is to be surface-joined to the ceiling board, the occurrence of cracks in the ceiling board can be reduced, and if the ceiling board is cracked, However, it is possible to reduce the occurrence of cracks from the ripples and to prevent the broken ceiling plate from dropping in pieces. In other words, since the face material in which the cable body is embedded is not the simple face material, but the surface material is entirely surface-bonded to the ceiling board, there is a cable body even if the ceiling board is cracked. Thus, the range in which the cracks are propagated in a limited manner is limited, and the occurrence of fragmentary ceiling plate drops due to the fastening force of the cable body is reduced.
Thereby, it is possible to more effectively prevent both the partial dropout and the total dropout of the ceiling board.

In the present embodiment, the first sheet 111 and the second sheet 112 are made of resin. However, the present invention is not limited to this, and a necessary strength can be obtained with a predetermined weight or less. As long as it is a thing, metal, wooden, cloth (fiber sheet), etc. may be sufficient, for example. However, it is preferably at least made of a non-brittle material that is more brittle than gypsum board (hard to break).
In the present embodiment, the face material 11 has a two-layer structure of the first sheet 111 and the second sheet 112, but may have a three-layer structure or more.

  In the present embodiment, the face material 11 is laid between the field edges 23, but the present invention is not limited to this. For example, the face material 11 straddles the field edges 23 ( It may be laid so as to cover the field edge 23).

<Embodiment 2>
In the first embodiment, the face material 11 is configured by the first sheet 111 and the second sheet 112 which are sheet-like members. However, in the second embodiment, a resin material having fluidity is used. What forms the face material 11 by apply | coating to the ceiling back side of the ceiling board 27 is demonstrated.
Since the structure of the existing suspended ceiling and the configuration of the cable body 12 and the fall prevention tool 13 are the same as those in the first embodiment, the description thereof is omitted here.

Hereinafter, the construction procedure of the ceiling board fall prevention structure of the present embodiment will be described.
Although the construction method is different from that of the first embodiment, the construction process is not greatly different from that of the first embodiment and will be described with reference to FIG.

Step 1
First, the upper surface (the surface on the back side of the ceiling) of the ceiling board 27 is cleaned (similar to the first embodiment).
Procedure 2 (Fig. 3 (a))
Next, a resin material is applied between the field edges 23, and the first resin layer 111 is formed on the surface of the ceiling plate 27 that becomes the ceiling back side.
Procedure 3 (Fig. 3 (b))
Next, before the 1st resin layer 111 dries, the cable body 12 and the fall prevention tool 13 are installed. The cable body 12 has a length that allows both ends of the cable body 12 to reach the housing (wall, column, beam, etc.), and is installed on the first resin layer 111. Etc.). The fastening of the cable body 12 and the housing is the same as in the first embodiment.
The fall prevention tool 13 is installed so that the hook 131 is hooked to the field edge 23.
Procedure 4 (Fig. 3 (c))
Finally, before the first resin layer is dried, a resin material is applied so as to cover the cord body 12 and the fall prevention tool 13 to form the second resin layer 112. As a result, the face material 11 in which the cable body 12 and the flange portion 132 of the fall prevention tool 13 are embedded is surface-joined to the ceiling plate 27 entirely.
After a predetermined drying time, the construction state is checked and the work is finished.

As described above, according to the present embodiment, the face material 11 in which the cable body 12 and the flange portion 132 of the fall prevention device 13 are embedded is integrally formed. It is the same as in the first embodiment in that the construction can be performed only from the back side of the ceiling and that both the partial dropout and the total dropout of the ceiling board can be prevented more effectively.
Here, an example is given in which the second resin layer 112 is applied before the first resin layer 111 is dried, so that the two are integrally formed. However, the first resin layer 111 is dried. After that, the second resin layer 112 may be applied.

  In this embodiment, the resin material is applied between the field edges 23, but the present invention is not limited to this. For example, the resin material is applied so as to cover the field edges 23. It doesn't matter.

In the installation work of the cable body 12 in each embodiment, it is necessary to install the cable body 12 between the field receiver 22 and the ceiling board 27 for a relatively long distance, and there is a surface that is not very good in workability. . In order to increase the efficiency of this work, a messenger wire, a PP rope, or the like may be passed first, and a plurality of ropes 12 may be connected to the messenger wire, a PP rope, or the like.
The cable body 12 is installed on the adhesive surface of the first sheet 111 or the first resin layer 111 that is not dried. There is a surface where the workability of the work of installing the ceiling plate 27 is not so good. On the other hand, you may make it provide the cylindrical body (pipe) for the efficiency improvement of the installation work of the rope body 12. FIG. FIG. 4 shows such an example.
The cylindrical body 14 is placed on the bonding surface of the first sheet 111 or the first resin layer 111 that is not dried, and the cable body 12 is passed through the cylindrical body 14, thereby The work efficiency of installation is improved. In addition, by previously passing a messenger wire, a PP rope, or the like through the tubular body 14, the work of passing the rope body 12 can be made more efficient as described above.
In the case of the construction method, as shown in FIG. 4, the tubular body 14 is embedded in the face material 11, and the rope body 12 is arranged inside the tubular body 14.

In each of the above embodiments, the fall prevention tool 13 has the flange portion 132, and the flange portion 132 is embedded in the face material 11 to prevent the face material 11 from falling. In order to further enhance the fall prevention function, the fall prevention devices 13 may be connected to each other. FIG. 5 shows such an example.
A connecting member that connects the fall prevention devices 13 to each other, and includes a connecting member 15 that is embedded in the face material 11, so that the face material 11 can be prevented from dropping and cracks spread to the ceiling plate. It is possible to enhance each of the function of reducing the height and the function of reducing the occurrence of fragmented ceiling plate dropping.
The connecting member 15 is formed of a stainless steel rope or the like, and is embedded in the face material 11 by being placed on the adhesive surface of the first sheet 111 or the first resin layer 111 in the same manner as the cable body 12. It can be.

Further, the surface area of the flange portion 132 may be increased in order to increase the bonding force between the fall prevention tool 13 and the face material 11. FIGS. 6B and 6C show such an example.
FIG. 6B is an example in which the joining force between the fall prevention tool 13 and the face material 11 is increased by using a flange portion 132 ′ having a hole.
FIG. 6C shows an example in which the joining force between the fall prevention device 13 and the face material 11 is increased by using a flange portion 132 ″ provided with a plurality of branch-like members.
In each embodiment, the fall prevention device is an example that is hooked on the field edge, but it is fastened or hooked to any of the field edge receiver, clip, hanger, and suspension bolt. It may be.

In addition, the fall prevention device is not fastened or hooked to the field edge or the like (or in addition to the hook to the field edge, etc.) but directly to the frame or through other members. May be. For example, an anchor bolt may be placed on a ceiling slab (or upper floor slab) to attach a hardware (attachment fitting), and this and a fall prevention tool may be fastened with a stainless steel rope or the like. FIG. 7 shows an example of a fall prevention tool for performing such fastening. Each of the fall prevention devices shown in FIGS. 7A to 7C is formed with a hole for fastening a rope body (stainless steel rope or the like) on the top of each fall prevention device of FIGS. The connecting portion 133 is provided.
7 (a)-(c), the load applied to the field edge, etc., is configured by suspending each fall prevention device by a rope fastened to a hardware provided on a housing such as a ceiling slab. Since it can reduce, it is more preferable.
In addition, although the fall prevention function is improved as described above by using the fall prevention tool 13, the face material in which the cable body is embedded is only surface-bonded to the ceiling board. However, since the fall prevention function can be obtained, the fall prevention tool 13 is not an essential element.

In each embodiment, although the rope body 12 was embedded in the face material 11 except for both ends thereof, the present invention is not limited to this. It is only necessary that the cable body 12 is bonded to the face material 11 with a necessary strength. For example, the cable body 12 may be partially exposed from the face material 11. .
Further, the rope 12 and the connecting member 15 are stainless steel ropes as an example, but the present invention is not limited to this (various steel wires or fiber ropes or the like as long as they have the required strength). I do not care).
In each embodiment, as an example, two cord bodies 12 are arranged between the field edges 23 as an illustration, but the present invention is not limited to this, and three or more (or one) ). Further, the cords arranged on the face material may be arranged in a lattice shape or a net shape.

11. . . Face material 111. . . First sheet (first resin layer)
112. . . First sheet (second resin layer)
12 . . Cord body 13. . . Fall prevention tool 14. . . Cylindrical body 15. . . Connecting member

Claims (14)

A ceiling plate fall prevention structure in a suspended ceiling structure in which the ceiling plate is suspended and held,
The ceiling board fall prevention structure characterized by the surface material by which the cable body is embedded or joined to the surface used as the ceiling back side of the said ceiling board being surface-joined.   The ceiling board fall prevention structure according to claim 1, wherein the cable body is fastened to a housing.   A fall prevention tool for reducing the fall of the face material, which is fastened or latched to any one of a field edge, a field edge receiver, a clip, a hanger, and a hanging bolt, and a part of the face material is The ceiling plate fall prevention structure according to claim 1 or 2, further comprising a fall prevention tool embedded or joined.   A fall prevention tool for reducing the fall of the face material, which is fastened to the housing directly or via another member, and the fall is partially embedded or joined to the face material The ceiling board fall prevention structure according to claim 1 or 2, further comprising a prevention tool.   5. The ceiling plate fall prevention structure according to claim 3, further comprising a connecting member that connects the fall prevention devices to each other and is embedded in or joined to the face material. .   The ceiling board fall prevention structure according to any one of claims 1 to 5, wherein the face material is formed of a plurality of layers, and the cable body is arranged between the layers of the face material.   The ceiling board fall prevention structure according to any one of claims 1 to 6, wherein the cable bodies are arranged substantially parallel to a field edge.   The tubular body embedded or joined to the face material is provided, and the cable body is arranged inside the tubular body. Ceiling plate fall prevention structure. A ceiling plate fall prevention method in a suspended ceiling structure in which the ceiling plate is suspended and held,
A ceiling plate fall prevention method comprising the step of surface-bonding a face material in which a cable body is embedded or joined to a surface which becomes a ceiling back side of the ceiling plate.   The ceiling board dropping prevention method according to claim 9, further comprising a step of fastening the cable body to the frame. The step of surface joining the face materials comprises:
Surface-bonding the first sheet to the surface of the ceiling plate that becomes the ceiling back side;
Disposing the cable body on top of the first sheet;
A step of surface-bonding a second sheet on top of the first sheet on which the cords are arranged;
The ceiling board falling prevention method according to claim 9 or 10, characterized by comprising: The step of surface joining the face materials comprises:
Forming a first resin layer by applying a resin material having fluidity to a surface of the ceiling plate that becomes the ceiling back side;
Disposing the cable body on top of the first resin layer;
Applying a resin material having fluidity to the upper part of the first resin layer in which the cords are arranged to form a second resin layer;
The ceiling board falling prevention method according to claim 9 or 10, characterized by comprising:   Fastening or latching a fall prevention tool for reducing the fall of the face material to any one of a field edge, a field edge receiver, a clip, a hanger, and a suspension bolt; and the fall prevention tool on the face material And a step of embedding or joining a part of the ceiling plate dropping prevention method according to claim 9.   Fastening the fall prevention tool for reducing the fall of the face material directly to the housing or via another member; and embedding or joining a part of the fall prevention tool to the face material; The ceiling board fall prevention method according to any one of claims 9 to 12, further comprising:

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