JP2004027735A - Underfloor termite prevention structure and underfloor termite prevention method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a termite prevention technology having excellent termite prevention effect even without using a termite prevention agent and easy to be implemented. <P>SOLUTION: An underfloor termite prevention structure is provided with a storage recessed part 20 arranged on a ground face E adjacent to a foundation structure 10 in an underfloor space U, a moisture-proof layer 22 arranged along an inner face of the storage recessed part 20, a moisture absorbing and discharging powder layer 24 stored on the moisture-proof layer 22 inside the storage recessed part 20, and a weight granular material layer 26 arranged on the moisture absorbing and discharging powder layer 24 inside the storage recessed part 20. The moisture absorbing and discharging powder 24 adheres to a termite to absorb water from the body of the termite and discharge it into the environment so that the termite of which water is deprived dies. <P>COPYRIGHT: (C)2004,JPO

Description

【００２８】
＜評価＞
（１）　コンクリート製試験支持体のみからなる試験構造３では、１週間で既に白蟻の這い上がりが始まり、３週間後には全面で白蟻が這い上がってしまい、食害も進んでしまっている。
（２）　吸放湿性粉体層を有する試験構造１および試験構造２では、４週間を経ても、白蟻の這い上がりは認められず、当然、白蟻の食害も発生していない。
（３）　試験構造２では、重し粒状物層が吸放湿性粉体層の上を覆っているが、防蟻機能の上では、全く問題が無いことが判る。
【００２９】
なお、試験構造１では、風などで吸放湿性粉体が飛散することがあったが、試験構造２では、吸放湿性粉体の飛散は全く起こらなかった。
【００３０】
【発明の効果】
本発明にかかる床下防蟻構造および床下防蟻工法は、基礎構造に隣接する地盤面の収容凹部に、防湿層、吸放湿性粉体層および重し粒状物層を備えている。
基礎構造に這い上がろうとする白蟻に、微細な粉体からなる吸放湿性粉体が付着し、白蟻の体内から水分を奪い取って空気中に放出してしまう。水分を奪い取られた白蟻は死滅してしまう。吸放湿性粉体と地盤との間には防湿層が存在するので、吸放湿性粉体が地盤の湿気などを吸って防蟻機能が損なわれてしまうことが、確実に防止できる。風などで飛散し易い吸放湿性粉体層の上に重し粒状物層が配置されているので、吸放湿性粉体層が飛散して散逸してしまい防蟻機能が損なわれてしまうことも防げる。その結果、吸放湿性粉体層の防蟻機能が長期間にわたって確実に発揮される。重し粒状物は、吸放湿性粉体層を完全に塞いでしまうことがないので、白蟻は、重し粒状物層の上だけを通過してしまうことはなく、確実に吸放湿性粉体と接触する。
【図面の簡単な説明】
【図１】本発明の実施形態を表す床下防蟻構造の断面図
【符号の説明】
１０　　布基礎
２０　　収容溝
２２　　防湿シート
２４　　吸放湿性粉体層
２６　　重し粒状物層
Ｅ　　　地盤
Ｕ　　　床下空間[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an underfloor termite structure and an underfloor termite construction method, and more particularly, to an underfloor termite structure that prevents invasion of termites from the ground to a foundation structure and an underfloor structure in a floor space of a building such as a house. The present invention is directed to a method for constructing such an underfloor termite structure.
[0002]
[Prior art]
As a countermeasure against termites in the underfloor space of a building, there is a technology to dig a groove in the surrounding ground for a foundation structure such as a cloth foundation or a bundle pillar and fill the groove with a liquid or powder termite agent. Are known. Termites trying to crawl up the underlying structure are killed by contacting termites as they cross the surrounding groove.
In addition, technology to cover the ground surface around the base structure with a termitic sheet impregnated with termite-controlling agents, apply termite-controlling agents to the outer peripheral surface of the base structure, or attach an termite-controlling sheet Is also known.
[0003]
As termiticides used in these techniques, arsenic, coal tar, chlordane, organophosphorus drugs, synthetic pyrethroids and the like are known.
In recent years, there has been an increasing interest in the problem of chemicals in residential environments, and termite control techniques using as little as possible a termiticide have been considered.
For example, Japanese Patent Application Laid-Open No. 2000-291170 discloses that a termite-controlling member made of a polyamide resin has a function of preventing termites from eating damage, a repelling effect, and a function of inhibiting formation of an ant passage.
JP-A-2000-26218 discloses a technique in which particles of colemanite, which is a natural mineral having an insecticidal effect on termites, are sprayed or deposited in layers.
[0004]
[Problems to be solved by the invention]
The conventional chemical-free termite control technology has a problem that the termite control effect is inferior to the case where a termiticide is used, or that the construction is troublesome.
Although the termite-controlling member made of the polyamide resin is effective in preventing and repelling termites, it does not kill termites. For this reason, there is a concern that termites may invade avoiding the termite-controlling members.
In the above-described method using colemanite particles, if the particle diameter is large, termites pass through the gaps between the particles, and the termite prevention function cannot be achieved. If the particle size is small, it will scatter. In addition, when moisture in the ground is absorbed, the termite control function is reduced. Even natural minerals contain components that have an insecticidal function, so workers under the floor must avoid inhaling or contacting them.
[0005]
It is an object of the present invention to provide a termite control technique that is excellent in termite control effects and easy to construct even without using a termiticide.
[0006]
[Means for Solving the Problems]
The underfloor termite structure according to the present invention is a termite structure in the underfloor space of a building, and includes a housing recess arranged on a ground surface adjacent to a foundation structure of the underfloor space, and an inner surface of the housing recess. An arranged moisture-proof layer, a moisture-absorbing and moisture-absorbing powder layer accommodated on the moisture-proof layer inside the accommodation recess, and a weight arranged on the moisture-absorbing and moisture-absorbing powder layer inside the accommodation recess. And a granular material layer.
[Underfloor space]
It can be applied to the underfloor space of various buildings such as general houses and apartment houses.
[0007]
The underfloor space is a space surrounded by an upper structure such as a floor or a wall of a building, a foundation structure such as a fabric foundation, and a ground surface.
The foundation structure is constructed of concrete, reinforced concrete, concrete block, and the like, and includes structures called cloth foundation, bundle foundation, and the like.
In the underfloor space, various facilities such as pipes and ducts may be installed, and such facilities can be considered as a part of the basic structure.
Termites enter the underfloor space from within the ground, crawl up the foundation structure and invade the superstructure, causing damage.
[0008]
(Accommodation recess)
It is placed on the ground surface adjacent to the foundation structure of the underfloor space. It constitutes a storage space for the moisture-absorbing and releasing powder layer.
The accommodation recess is arranged along a boundary between the foundation structure and the ground surface. In the underfloor space surrounded by the cloth foundation, a groove-shaped accommodation recess can be provided along the cloth foundation all around the underfloor space. In the case of an independent foundation structure, such as a bundle foundation, the receiving recess can be provided annularly along the outer periphery of the foundation structure.
The housing recess may be provided independently on the ground remote from the side surface of the foundation structure, but one inner side surface may be constituted by the side surface of the foundation structure. If the housing recess is in contact with the side surface of the basic structure, termites can be prevented from passing through the gap between the housing recess and the basic structure.
[0009]
The cross-sectional shape of the housing recess may be an inverted trapezoidal shape narrowing in the depth direction, a rectangular shape, a triangular shape, a U-shape, a semicircular shape, or the like.
The depth and width of the storage recess can be set in accordance with the amount of the hygroscopic powder to be stored. It is preferable that the width is such that the termites that traverse the accommodation recess can reliably contact the hygroscopic powder. It is desirable to have a sufficient depth so that the moisture-absorbing / desorbing powder layer does not disappear even if the moisture-absorbing / desorbing powder adheres to the termite and is taken out. Specifically, the width on the opening side of the housing recess can be set in a range of 5 to 50 cm, and the depth can be set in a range of 2 to 50 cm.
(Moisture-proof layer)
Prevents moisture and moisture in the ground from being absorbed by the moisture absorbing and releasing powder layer.
[0010]
The moisture-proof layer is arranged along the inner surface of the accommodation recess. A moisture-proof layer is provided at least in a range that comes into contact with the moisture-absorbing and releasing powder. It is preferable to dispose even the portion where the weight particulate layer is accommodated. Further, a part of the ground outside the opening edge of the housing recess and a part of the surface of the foundation structure can be covered with the moisture-proof layer.
The moisture-proof layer may be formed by applying and curing a moisture-proof liquid material made of a synthetic resin or the like, or a moisture-proof sheet formed in a sheet shape in advance may be laid. Examples of the material of the moisture-proof layer include polyethylene, ethylene-vinyl acetate copolymer, polyolefin resin such as polypropylene, polyamide resin, polyester resin, polyvinyl chloride resin, polyvinyl alcohol resin, acetylcellulose resin, and polyurethane resin. Non-woven fabrics can also be used. What laminated | stacked or compounded several materials can also be used.
[0011]
The thickness of the moisture-proof layer may be any thickness as long as it can surely block moisture and moisture, and varies depending on the material. However, it can usually be set in the range of 0.1 to 5.0 mm. In the case of a moisture-proof sheet, if it is 2 mm or less, handling such as deformation along the inner surface of the accommodation recess is easy to perform.
When a moisture-proof sheet is used, the moisture-absorbent sheet can be fixed by depositing the moisture-absorbing / desorbing powder and the weight particulate matter on the moisture-proof sheet laid in the accommodation recess. The moisture-proof sheet can be fixed with an adhesive or a nail. In order to fix the moisture-proof sheet to the basic structure, it can be attached with an adhesive or a pressure-sensitive adhesive. An adhesive tape or an adhesive tape can also be used.
[0012]
When sticking the edge of the moisture-proof sheet to the rising surface of the basic structure, it is effective to use a creep-up prevention tape that is slippery on the surface and that makes it difficult for termites to creep up. As a material for the creeping prevention tape, a film made of a synthetic resin such as a polyolefin resin such as polyethylene and polypropylene, a polyamide resin, a polyester resin, a polyvinyl chloride resin, a polyvinyl resin, a polyvinyl alcohol resin, and a polyurethane resin can be used. If the width of the anti-creep tape arranged on the vertical surface is 10 cm or more, it is difficult for termites to crawl over the anti-creep tape. It is also difficult for termites to make an ant path. When the anti-creeping tape contains an anti-termite agent composed of hiba oil, wood vinegar and other natural materials, the anti-termite function is enhanced.
[0013]
(Hygroscopic powder layer)
It is housed on the moisture-proof layer inside the housing recess. When attached to termites, it has the function of removing moisture from the termites and eventually killing the termites.
Silica gel, diatomaceous earth, porous minerals, carbides, and the like can be used as the moisture absorbing / releasing powder constituting the moisture absorbing / releasing powder layer. A plurality of materials can be used in combination.
The moisture-absorbing and releasing powder is preferably a fine powder to which termites easily adhere. Specifically, the particle size can be set to 0.1 mm or less.
(Weight granular layer)
It is arranged on the moisture absorbing / releasing powder layer inside the accommodation recess. It functions as a weight for preventing the fine powdery hygroscopic powder from scattering.
[0014]
Silica gel, diatomaceous earth, porous minerals, carbides, and the like can be used as the weight particles constituting the weight particle layer. A plurality of materials can be used in combination.
The particle size of the weight granules can be set in the range of 0.2 to 6.5 mm. If the weighted granular material is a granular material having moisture absorption and release properties, it prevents moisture contained in the air under the floor from being absorbed by the moisture absorption and release powder, and the termite prevention function of the moisture absorption and release powder Can be maintained satisfactorily over a long period of time.
In the weight particulate layer, the weight particulates do not need to be closely stacked without gaps, and a gap may be provided between the weight particulates. In addition, the weight particles may be arranged in a single layer.
[0015]
[Antitious construction method]
Step (a): An accommodation recess is formed on the ground surface adjacent to the foundation structure of the underfloor space. Using a scoop-shaped or plow-shaped tool corresponding to the cross-sectional shape of the storage recess, the storage recess can be formed by digging the ground.
Step (b): Laying a moisture-proof sheet along the inner surface of the accommodation recess. The moisture-proof sheet formed in a belt shape in advance can be spread in the accommodation recess. It is also possible to lay while unwinding a long wound moisture-proof sheet, or to arrange fixed-size moisture-proof sheets so as to partially overlap. If necessary, work to fix the moisture-proof sheet to the surface of the substructure or the ground. If a creep-up prevention tape or an adhesive tape is previously adhered to the moisture-proof sheet, or an adhesive layer or an adhesive layer is formed on the sheet, the moisture-proof sheet can be easily laid and fixed. Of course, after laying the moisture-proof sheet, it is also possible to attach a crawling prevention tape or the like.
[0016]
Step (c): forming a moisture-absorbing and desorbing powder layer by depositing the moisture-absorbing and desorbing powder on the moisture-proof layer inside the accommodation recess. The moisture-absorbing / desorbing powder can be supplied in a state of being stored in a bag or a container that does not allow moisture to enter, and can be deposited by being poured into a storage recess from a supply port provided in a part of the bag or the container.
Step (d): The superposed particulates are arranged on the moisture absorbing and releasing powder layer inside the accommodating recess to form a superposed particulate layer. The weight and particulate matter is sprayed to such an extent that the surface of the moisture-absorbing and releasing powder layer is almost covered. A part of the moisture absorbing and releasing powder layer may be exposed.
Other Steps: In addition to the above steps, ordinary termite control methods and termite control means can be combined as long as the effects of the present invention are not impaired. For example, a termite sheet can be laid on the ground surface, or termite tape can be attached to the foundation structure.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
[Anti-term underfloor structure]
The embodiment shown in FIG. 1 shows an ant-prevention structure in a cloth foundation portion in a space under the floor of a house.
As a basic structure of a house, a cloth foundation 10 made of a concrete frame having an inverted T-shaped cross section is constructed. The lower part of the cloth foundation 10 is buried in the ground E. The cloth foundation 10 has a peripheral frame shape surrounding the outer periphery of the house and is arranged so as to partition the inside into a plurality of sections. On the upper part of the cloth foundation 10, an outer wall 14 is constructed via a base 12, and a floor 18 is constructed via a joist 16 to construct an upper structure of a building. The space surrounded by the cloth foundation 10 between the floor surface 18 and the ground E is the underfloor space U.
[0018]
In the underfloor space U, an accommodation groove 20 having an inverted trapezoidal cross section is dug in the ground E at the base of the cloth foundation 10. The accommodation groove 20 is provided continuously around the entire circumference of the cloth foundation 10 in the underfloor space U. The inner surface on one side of the accommodation groove 20 is configured as a side surface that is a rising surface of the cloth foundation 10. The accommodation groove 20 is formed to have a width of 10 cm and a depth of 10 cm in the cross-sectional shape.
A moisture-proof sheet 22 made of polyethylene is laid from the surface of the ground E outside the accommodation groove 20 to the inner surface of the accommodation groove 20 to the side surface of the cloth foundation 10.
On the side surface of the cloth base 10, the end of the moisture-proof sheet 22 is adhered to the cloth base 10 with a creep-up prevention tape 28 made of nylon having a width of 10 cm and having an adhesive. Therefore, there is no gap between the cloth base 10 and the moisture-proof sheet 22 through which termites can enter. The opposite end of the moisture-proof sheet 22 may be fixed to the ground E with metal fittings or the like. By arranging the layer 26, the lifting of the moisture-proof sheet 22 can be prevented.
[0019]
Silica gel in the form of fine powder having an average particle size of 0.02 mm is deposited on the moisture-proof sheet 22 to form the moisture-absorbing and releasing powder layer 24. Since the moisture-proof sheet 22 exists between the moisture-absorbing and releasing powder layer 24 and the ground E, it is possible to prevent the moisture-absorbing and releasing powder 24 from absorbing the moisture of the ground E and lowering the moisture absorbing function. The moisture absorbing / releasing powder layer 24 is arranged near the upper end opening of the housing recess 20.
The surface of the moisture-absorbing / desorbing powder layer 24 is covered with a weight / particle layer 26 made of granular silica gel having an average particle size of 2.0 mm larger than that used in the moisture-absorbing / desorbing powder layer 24. The weight granular material layer 26 is arranged such that the weight granular material 26 substantially covers the moisture absorbing / desorbing powder layer 24, and there is a certain gap between the weight granular materials 26.
[0020]
(Antitermite action)
In the termite structure shown in FIG. 1, termites tend to enter the upper structures 12 to 18 from the ground E in the underfloor space U via the cloth foundation 10.
The termites cannot be transferred to the cloth base 10 if the termites are laid on the moisture-proof sheet 22 and crawl on the particulate layer 22 or the moisture-absorbing / desorbing powder layer 24.
The hygroscopic powder 24 made of fine powder adheres to the body of the termite moving on the hygroscopic powder layer 24. The hygroscopic powder 24 attached to the termite's body absorbs and retains moisture from the termite's body. The moisture absorbed by the hygroscopic powder 24 is released into the surrounding air. As a result, water disappears from the termite's body, and the termite dies.
[0021]
Note that the termites do not immediately die off by contacting the moisture-absorbing and desorbing powder layer 24 and die. Therefore, there are termites that cross the moisture-absorbing / desorbing powder layer 24 and reach the fabric base 10 with the moisture-absorbing / desorbing powder 24 attached. However, the hygroscopic powder 24 attached to the termites continuously acts to remove moisture from the body of the termites and release the moisture into the air. Will die. When the termites to which the moisture-absorbing and releasing powder 24 adheres return to the nest and come into contact with other termites, a part of the moisture-absorbing and releasing powder 24 is transferred to another termite and also has the effect of causing death.
Although some termites crawl on the weight and granular material layer 22 without touching the moisture absorbing and releasing powder layer 24, termites moving along the surface of the granular weight and granular material 22 inevitably have weight It passes through the position where it touches the hygroscopic powder 24 from the lower surface side. As a habit of termites, when trying to pass through a granular material, it is likely to touch the hygroscopic powder 24 under the weight granular material 22 because it tries to penetrate under the granular material. There is also an opportunity to touch the moisture absorbing / releasing powder 24 when passing between the adjacent weight granular materials 22. Therefore, it is almost impossible for termites to reach the cloth base 10 by crawling only on the weight granular material 22 without touching the moisture absorbing / releasing powder 24 at all.
[0022]
Further, even if the termites to which the moisture-absorbing and desorbing powder 24 adheres cross the moisture-absorbing and desorbing powder layer 24 and reach the cloth foundation 10, the termites existing on the edges of the moisture-proof sheet 22 can be prevented from rising. The slippery surface of tape 28 cannot be crawled vertically. The termites fall from the crawling-up prevention tape 28 to the weighted granular material layer 22 or the moisture-absorbing and desorbing powder layer 24, and the moisture-absorbing and desorbing powder 24 adheres.
Even if the termites to which the moisture-absorbing and desorbing powder 24 adheres can rarely reach the upper part of the cloth base 10 beyond the crawling prevention tape 28, the termites whose life force has been reduced due to deprivation of water over time are: The upper structure cannot be damaged or propagated more than the cloth foundation 10 of the house.
[0023]
When the upper surface of the moisture-absorbing / desorbing powder layer 24 is covered with the weight / granular material layer 22 having the moisture-absorbing / desorbing property, the moisture in the underfloor space U is absorbed before the moisture-absorbing / desorbing powder layer 24 absorbs the moisture. It is absorbed by the granular material layer 22. As a result, the moisture-absorbing and desorbing powder layer 24 is always kept in a dry state, and the adhesion and the moisture absorbing function to the termites are exhibited well. Further, by setting the entire environment of the underfloor space U to a dry state in which the termites dislike, there is also an effect of preventing invasion of termites into the underfloor space U.
(Performance evaluation test)
A test was performed to evaluate the termite-controlling effect of the termite-controlling structure of the present invention.
[0024]
The following three types of test structures were tested in accordance with the Japan Wood Preservation Association Standard No. 17, "Testing method and performance criteria for indoor termite control of non-wood products treated with termiticides".
<Test structure 1>
A receiving groove having a width of 10 cm and a depth of 10 cm from the outer surface of the support was formed around the concrete test support. A 200-μm-thick polyethylene moisture-proof sheet was placed on the bottom of the accommodation groove. On the moisture-proof sheet, a moisture absorbing / releasing powder composed of crushed silica gel B type (manufactured by Fuji Co., Ltd.) (average particle size: 0.02 mm) is deposited in an amount of 2 kg per 1 m in the length direction of the accommodation groove. I let it.
[0025]
<Test structure 2>
A receiving groove having a width of 10 cm and a depth of 10 cm from the outer surface of the support was formed around the concrete test support. A moisture-proof sheet made of polyethylene having a thickness of 150 μm was laid on the bottom of the accommodation groove. On the moisture-proof sheet, a moisture absorbing / releasing powder composed of crushed silica gel B type (manufactured by Fuji Co., Ltd.) (average particle size: 0.02 mm) is deposited in an amount of 2 kg per 1 m in the length direction of the accommodation groove. I let it.
On the moisture-absorbing and desorbing powder layer, Wakkanai diatomaceous earth particles (average particle size: 2.0 mm) were deposited as a weight particle layer in an amount of 3 kg per 1 m in the length direction of the accommodation groove.
[0026]
<Test structure 3>
Only concrete test supports were used. Do not use a moisture-proof sheet, a moisture-absorbing / desorbing powder layer, or a weight particulate layer.
<Test results>
[0027]
[Table 1]

[0028]
<Evaluation>
(1) In the test structure 3 consisting only of the concrete test support, the termites began to climb up in one week, and after 3 weeks, the termites crawled up in the entire surface, and the damage to the ants was advanced.
(2) In Test Structure 1 and Test Structure 2 having the moisture-absorbing and releasing powder layer, even after 4 weeks, no termite crawling was observed, and, of course, no termite damage occurred.
(3) In the test structure 2, although the weight particulate layer covers the moisture absorbing / releasing powder layer, it can be seen that there is no problem in terms of the termite control function.
[0029]
In the test structure 1, the moisture-absorbing and desorbing powder was sometimes scattered by wind and the like, but in the test structure 2, the scattering of the moisture-absorbing and desorbing powder did not occur at all.
[0030]
【The invention's effect】
The under-floor termite protection structure and the under-floor termite protection method according to the present invention include a moisture-proof layer, a moisture-absorbing and desorbing powder layer, and a weight particulate layer in an accommodation recess on the ground surface adjacent to the foundation structure.
The hygroscopic powder composed of fine powder adheres to the termites that are going to crawl on the basic structure, deprives the termites of water and releases them into the air. Termites that have been deprived of water will die. Since the moisture-proof layer exists between the moisture-absorbing and releasing powder and the ground, it is possible to reliably prevent the moisture-absorbing and releasing powder from absorbing moisture and the like in the ground and impairing the ant-control function. Because the particulate layer is placed on top of the moisture-absorbing and absorbing powder layer that is easily scattered by wind, etc., the moisture-absorbing and releasing powder layer scatters and dissipates, impairing the termite control function. Can also prevent. As a result, the termite-controlling function of the moisture-absorbing and releasing powder layer is reliably exhibited for a long period of time. The weight particles do not completely block the moisture-absorbing / desorbing powder layer, so the termites do not pass only over the weight-granulating material layer. Contact with.
[Brief description of the drawings]
FIG. 1 is a sectional view of an underfloor termite structure showing an embodiment of the present invention.
DESCRIPTION OF SYMBOLS 10 Cloth foundation 20 Storage groove 22 Moisture-proof sheet 24 Hygroscopic powder layer 26 Weight granular material layer E Ground U Underfloor space

Claims (4)

Termite structure in the underfloor space of the building,
An accommodation recess arranged on the ground surface adjacent to the foundation structure of the underfloor space,
A moisture-proof layer arranged along the inner surface of the housing recess,
A moisture-absorbing and desorbing powder layer housed on the moisture-proof layer inside the housing recess,
An underfloor termite structure comprising: a weight particulate layer disposed on the moisture absorbing / releasing powder layer inside the housing recess. The moisture absorbing / releasing powder constituting the moisture absorbing / releasing powder layer is any one selected from the group consisting of silica gel, diatomaceous earth, porous mineral, and carbide, and is a powder having a particle size of 0.1 mm or less. Yes,
The weight granules constituting the weight granule layer are any one selected from the group consisting of silica gel, diatomaceous earth, porous mineral, and carbide, and have a particle size of 0.2 to 6.5 mm. The underfloor ant-control structure according to claim 1, which is a granular material having moisture. The moisture-proof layer is a moisture-proof sheet laid along the inner surface of the housing recess,
The underfloor ant-proof structure according to claim 1 or 2, further comprising a crawling-up prevention tape for attaching an end of the moisture-proof sheet to a rising surface of the basic structure. Termite control method in the underfloor space of a building,
(A) forming an accommodation recess in a ground surface adjacent to a foundation structure of the underfloor space;
(B) laying a moisture-proof sheet along the inner surface of the housing recess;
(C) forming a moisture-absorbing and desorbing powder layer by depositing a moisture-absorbing and desorbing powder on the moisture-proof layer inside the housing recess;
A step (d) of arranging weight particles on the moisture-absorbing and desorbing powder layer inside the accommodation recess to form a weight particle layer.

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