AU2003244546A1 - Termite barrier - Google Patents

Description

TERMITE BARRIER FIELD OF INVENTION This invention relates to the protection of buildings from subterranean termites and is particularly concerned with physical termite barriers for incorporating into buildings during their construction.

BACKGROUND OF THE INVENTION Subterranean termites typically build nests just beneath the soil surface and forage, principally for cellulose-containing material, for distances which can reach hundreds of meters from their nests. Termite damage to buildings, particularly residential buildings, can be as many as one building in five in some parts of Australia, costing the community many tens of millions of dollars annually in the repair of the affected timber. As a result, the Australian Building Code has made it compulsory for all new buildings to incorporate suitable termite barriers.

Many forms of barriers have been proposed but only a limited number are in use. Cost, efficacy, safety and ease of installation are the prime considerations to be taken into account when designing termite barriers. Many barriers meet one, two or even three of these considerations, but generally not all. Those which come closest are the pesticidal blankets. These generally comprise either a single pliable sheet of plastics, paper or like material in which a termiticide is incorporated, or a double sheet of pliable plastics material with a layer of termiticide trapped between the sheets either in a layer or in a fibrous material.

The problem with the single sheet construction, however, is that it is difficult to effectively incorporate the termiticide into the structure without significantly reducing its potency. The problem for both the single and double sheet constructions is that eventual leaching and/or degradation of the termiticide means that the life of the barrier can be quite short and as a consequence, its effectiveness can quickly be reduced to zero.

OBJECT OF THE INVENTION It is therefore an object of the invention to provide a termite barrier which overcomes or at least reduces the aforementioned problems, or at least provides the public with a useful alternative.

STATEMENT OF THE INVENTION According to the present invention there is provided a termite barrier comprising a layer of fibrous material impregnated with a termiticide and bonded to a rigid sheet of polyvinylchloride having a shore hardness of greater than about BRIEF DESCRIPTION OF THE DRAWING Various examples of the invention are described, by way of example only, with reference to the accompanying drawings, in which: Figs 1 and 2 are vertical sections through part of a wall, according to the invention, Figs 3 and 4 are vertical sections through part of a floor slab, Figs 5 and 6 are vertical and plan views respectively of a post or pier, Figs 7, 8 and 9 are vertical sections through walls or piers, Figs 10, 11, 12, and 13 are vertical sections through parts of walls and floor slabs, Figs 14 and 15 are perspective views and vertical sections respectively through knock-out block constructions, Fig.16 shows part of Fig. 15 at enlarged scale, Figs 17, 18 and 19 are vertical sections through floor slabs, Fig 20 is a plan view of a rebate board, Figs 21 to 29 are other vertical sections through concrete floors, Fig 30 shows perspective views of sections through different wall/floor design, Fig 31 shows a vertical section through another floor construction, Figs 32, 33 and 34 are vertical sections through parts of walls, Fig 35 shows a perspective and vertical sections of a collar, Fig 36 shows a vertical section through another slab, Figs 37, 38 and 39 are perspective views of other embodiments, and Fig 40 shows alternative blockwork constructions.

DESCRIPTION OF THE INVENTION By providing a layer of fibrous material which is exposed on one side, it is possible to readily recharge the termiticide by simply spraying or injecting straight into the exposed portion of the fibrous material, and capillary action will then cause the termiticide to migrate throughout the remainder of the non-exposed portion of the fibrous material. In this way, the problems of the prior art barriers referred to above, are effectively overcome.

Also, by providing a rigid backing of polyvinylchloride, the barrier has a second or back-up defense against the penetration of termites, that is, its thickness and impenetrability. In the prior art, the pliable sheets used to contain the termiticide are readily subject to damage by tearing during installation, or, because they are so thin, destruction by the termites themselves. Furthermore, such prior art barriers are not particularly suitable for use in applications around piers because of their pliability and inability to be properly installed.

The fibrous material in the barrier of the present invention is preferably in the form of matting which is most preferably synthetic in nature. Suitable fibrous materials include but are not limited to polyethylene, polypropylene, polybutylene, polyacrylonitrile, polymethylmethacrylate, polyurethane, nylon 66 polyvinylchloride, polyvinylacetate, acrylate-styrene-acrylonitrile fibres, as well as fibres formed from various polyesters, polyamides, silicones, butyl and neoprene rubbers, and the like. The fires can be woven, layered, comminuted or otherwise physically processed to form a matting which is of a suitable density and thickness for the specific application of use. Generally, the density will be in the range of about 100 to 300g/m 2 preferably about 200 g/m 2 and the thickness will be between about 1mm and 3mm, preferably about 2mm.

The termiticide can be any material known to kill or repel termites and includes such materials as bifenthrin, fibroonil, chlorophifos, boracol, isofenphos, fenvalerate, cypermethrin, permethrin, pyrethrin, tefluthrin, lambdacyhalothrin, cyfluthrin, deltamethrin, and combinations thereof. Carriers and dilutants, as well as other active ingredients such as fungicides and herbicides, can also be included with the termiticide to provide a multifunctional all-purpose composition.

Preferably, the termiticides is impregnated into the fibrous material after the fibrous material has been co-joined to the rigid sheet of polyvinylchloride.

The polyvinylchloride sheet preferably has a minimum thickness of about 1mm to ensure that the required degree of rigidity and impenetrability is obtained.

The sheet is preformed with the profile required for the particular intended application, by extrusion moulding. Thus, for example, flat sheets are produced for under slab situations, cap-profile elements are produced for capping of piles, and strips with angled formations are produced for extending along the perimeters of buildings. Preferably, a UV stabilizer is incorporated into the polyvinylchloride sheet during its manufacture to prevent or minimise degradation by sunlight.

The bonding of the fibrous material to the polyvinylchloride sheet is such as to provide a termite-impervious connection. To this end the bonding can be by physical lamination or by chemical adhesion. Physical lamination comprises heat and pressure bonding whereby the layer of fibrous material is laid over the sheet of polyvinylchloride while pressure and heat is supplied for a sufficient time to enable at least one of the two materials to melt or soften and to form a strong mechanical bond with the other of the materials. Chemical adhesion comprises the use of a termite resistant adhesive, such as an epoxy or solvent cement, e.g.

Bondcrete which is preferably spread over the entire surface of the polyvinylchloride sheet followed by the overlay of the fibrous material. Curing can occur naturally or with the assistance of heat and/or pressure.

The termite barrier according to the present invention can be used in most building applications where termite entry is to be prevented. It can be laid under monolithic concrete slabs, and fitted to retaining walls, footings, piers, building perimeters and the like, with the aid of termite resistant fixtures and/or adhesives.

Examples of such use are shown in the following description and drawings wherein the term "Plasmite" is a term coined by the applicant to refer to the termite barrier of the invention.

Figures 1 and 2 show how Plasmite Termite Barrier sheets 10 are to be solvent cement glued to each other with an overlap 11 of at least 75mm. The Figures show Plasmite sheets 10 nailed to retainer wall 12 which stands on a footing 13, to hold it into place. The nails are epoxyed over. Epoxy or "liquid nails" glue could also be used. Beads of Plasmite epoxy 14 are provided along the base of the sheets In Figure 3 Plasmite sheets 10 are solvent cemented together to cover the entire surface of compacted landfill 15. The Plasmite sheets overhang the compacted fill by at least 50mm and Plasmite protection is required around the perimeter.

Figure 4 shows that termites cannot gain access to a structure via a crack 16 because of the Plasmite barrier Figure 5 and 6 show a post or pier 16 standing on the ground 17.

Termites are prevented from climbing up into a building supported by the post 16 by a Plasmite sheet 10 overlapping the top of the post 16. A bead of Plasmite epoxy 18 surrounds a tie-down rod 19.

Figure 7 shows a single brick wall 12 standing on the footing 13 and protected by 3 metre lengths of the Plasmite barrier 10 cemented together with a 75mm overlap.

In Figure 8 bearers 20 rest on one leaf of the double wall 12. The Plasmite barrier 10 extends across both leaves of the wall 12, below the bearers In Fig 9 attached piers 16 have overlapping Plasmite barrier sheets Figures 10, 11, 12 and 13 show various ways of installing Plasmite by nailing, and epoxy gluing, to various slab formations 21.

Figures 14 and 15 show how Plasmite termite barrier sheets 10 are placed onto the top of a knock-out block 22 and glued down with epoxy onto the slab 21. The Plasmite strips are joined by solvent cement glue.

Figure 16 shows part of Figure 15, at enlarged scale. It shows a tie-down rod or reinforcing rod 19 passing through the slab 21 and the knock-out block 22.

Figure 17 and 18 show slabs 21 with Plasmite barrier sheets 10 spanning a joint between the slabs 21. In Figure 18 the Plasmite barrier sheet 10 is nailed to the existing slab 21 and embedded in the right-hand slab 21 when it is poured.

Figure 19 shows Plasmite termite barrier 10 supplied in 3 meter lengths.

It is placed onto the top of brick work 23 and joined together using solvent plumber's glue for overlapping joins of 75mm. Liquid Nails is placed on brick work 23 before placing strip shield 10 to assist in holding it down if in windy conditions. If rebate boards are used, holes should be punctured through the Plasmite termite barrier 10. Holes 24 could be patched by either Plasmite epoxy or solvent cement by gluing a piece of strip shield 10 over the hole, as shown in Figure Figure 21 shows a double brick wall 12 on a boxed footing 13 which also carries the slab 21.

Figure 22 shows how Plasmite termite barrier 10 is placed on a brick and slab construction in the correct position and glued to the slab 21 with epoxy.

Figure 23 shows how Plasmite termite barrier 10 is placed in 3 meter lengths and nailed into slab 21 at least 400mm intervals and glued together with solvent cement with 75mm overlaps. Plasmite epoxy is then used to seal the gap between the slab edge and Plasmite strip shielding 10. Plasmite epoxy is placed into a spoon/hip at the top of the strip shield. If honeycombing of the slab edge has occurred it is rendered smooth using high strength/non-shrink grout compound at the height the strip shield is to be placed.

In Figure 24 the barrier sheet 10 is fastened by nails 25 of which the heads are sealed with Plasmite epoxy 26.

Figure 25 shows a Plasmite termite barrier "Epoxy Seal" 26, between the concrete and plumbing/electrical pipes 27 passing through concrete slabs 21, to stop termite entry.

Figures 26, 27, 28 and 29 show the use of Plasmite termite barrier Epoxy Seal" 26, between concrete and concrete as in control joints, dowel joints 28 and key joints 29 in concrete slabs 21 to stop termite entry.

The left-hand view in Figure 30 shows a conventional cavity brick wall while the right-hand view shows a conventional brick and internal veneer wall. In both cases the Plasmite barrier sheet 10 extends from the outside to the inside of the wall 12 below floor level Figure 31 shows how the termite barrier 10 has a horizontal length which extends through a bricked up base and a downwardly inclined portion to be cast into the concrete slab 21. The termite barrier 10 has a turned-up edge to lock into the concrete 21.

Figure 32 is similar to Figure 5 but shows the post/pier 16 made of steel, timber or other suitable material.

Figure 33 shows Plasmite termite barrier 10 embedded in the footing 13 of the retainer wall 12.

In Figure 34 the slab 21 may be provided with reinforcing mesh 31.

Figure 35 shows how a Plasmite collar 30 is cut and folded to fit on the pipe 27.

Figure 36 shows the Plasmite collar 30 fastened with epoxy to the top of the concrete slab 21 and around the pipe 27.

Figures 37, 38, 39 and 40 show various uses of the Plasmite barrier 10 in different wall and floor configurations.

Whilst the above has been given by way of illustrative example of the invention, many modifications and variations may be made thereto by persons skilled in the art without departing from the broad scope and ambit of the invention as herein set forth.

Claims (10)

1. A termite barrier comprising a layer of fibrous material impregnated with a termiticide and bonded to a sheet of polyvinylchloride having a shore hardness of greater than about

2. A termite barrier, according to claim 1, in which the layer of fibrous material is exposed on one side, and it is possible to recharge the termiticide by spraying or injecting straight into the exposed portion of the fibrous material, and capillary action will then cause the termiticide to migrate throughout the remainder of the non-exposed portion of the fibrous material.

3. A termite barrier according to claim 1 or 2 in which the sheet of polyvinylchloride is rigid, whereby the barrier has a second or back-up defense against the penetration of termites, that is, its thickness and impenetrability.

4. A termite barrier according to any preceding claims, in which the barrier is in the form of matting which is synthetic in nature. A termite barrier according to claim 4 in which the fibrous materials include polyethylene, polypropylene, polybutylene, polyacrylonitrile, polymethylmethacrylate, polyurethane, nylon 66 polyvinylchloride, polyvinylacetate, acrylate-styrene-acrylonitrile fibres, as well as fibres formed from various polyesters, polyamides, silicones, butyl and neoprene rubbers.

6. A termite barrier according to claim 4 or 5 in which the fibres are woven, layered, comminuted or otherwise physically processed to form a matting which is of a suitable density and thickness for the specific application of use.

7. A termite barrier, according to claim 6, in which the density is in the range of about 100 to 300 g/m 2 preferably about 200 g/m 2 and the thickness will be between about 1mm and 3mm, preferably about 2mm.

8. A termite barrier, according to any preceding claim, in which the termiticide includes bifenthrin, fibroonil, chlorophifos, boracol, isofenphos, fenvalerate, cypermethrin, permethrin, pyrethrin, tefluthrin, lambdacyhalothrin, cyfluthrin, deltamethrin, and combinations thereof.

9. A termite barrier, according to any preceding claim, in which the termiticide is impregnated into the fibrous material after the fibrous material has been co- joined to the sheet of polyvinylchloride. termite barrier, according to any preceding claim, in which the fibrous material and the sheet of polyvinylchloride are bonded together by laying the fibrous material over the sheet of polyvinylchloride while pressure and heat is supplied for a sufficient time to enable at least one of the two materials to melt or soften and to form a strong mechanical bond with the other of the materials.

11. A termite barrier according to any of claims 1 to 9 in which the fibrous material and the sheet of polyvinylchloride are chemically bonded together by the use of a termite resistant adhesive, such as epoxy or solvent cement, e.g. Bondcrete®, which is spread over the entire surface of the polyvinylchloride sheet followed by the overlay of the fibrous material.

12.A termite barrier constructed and arranged and adapted to operate substantially as described herein and as shown in the accompanying drawings. DATED this 4 th day of September 2003 Anthony Mark Anderson By his Patent Attorneys Pipers Patent and Trade Mark Attorneys