AU7613998A - Termite barrier - Google Patents

Description

-2 The present invention relates to the control of termites in relation to buildings and other structures and in particular provision of a termite barrier between a structure (such as a concrete slab) and an object (such as a conduit) extending therethrough. 5 Australian Patent Application No. 61772/94, the contents of which are incorporated herein by way of reference, discloses techniques for protecting a building or like structure against the entry of termites using termite barrier material. The disclosure includes an arrangement for preventing the passage of termites through a gap which might exist between an opening in a concrete slab 10 and a conduit accommodated within the opening to extend through the concrete slab. The arrangement comprises a sleeve of barrier material which is, in use, located about the periphery of the conduit and clamped in pressure engagement therewith about the complete perimeter of the conduit, and an integral flange formed of said barrier material projecting from said sleeve, the integral flange in 15 use being sealably embedded in the slab. Embedding of the flange in the concrete is a particularly convenient way of attaching the barrier material to the concrete slab. Accordingly, the present invention provides a termite barrier comprising a body having an aperture extending therethrough to sealingly receive an object therein 20 and an outwardly extending flange portion surrounding the aperture, the flange portion being adapted to be at least partly embedded in a concrete structure through which in use the object extends. The body may sealingly receive the object in the aperture in any suitable fashion. In one arrangement, the aperture may be dimensioned to provide a 25 sufficiently close fit between the body and the conduit to prevent the passage of termites through the aperture. In another arrangement, the body may be in sealing engagement with the object. In the latter arrangement, the sealing -3 engagement may be in any suitable form such as frictional engagement or pressure engagement achieved by a clamping action applied to the body. The flange portion may be embedded entirely in the concrete or a section thereof only may be embedded in the concrete. 5 The flange portion may have a surface configured for gripping engagement with the concrete structure in which it is in use embedded to provide sealing therebetween against the entry of termites. The configuration of the surface may provide keying between the flange portion and concrete. The gripping engagement between the flange portion and the concrete 10 maintains the integrity of sealing between the flange portion and the concrete in circumstances where the concrete is subject to normal shrinkage. The body may comprise a sleeve which surrounds and defines the aperture. The sleeve and flange portion may be formed integrally with each other. In one arrangement, the flange portion may comprise mesh material. Indeed, the 15 body may be formed entirely of mesh material. The mesh material may be of the type described in Patent Application No. 61772/94, although such mesh material may still be effective with a hardness reduced from not less than about Shore D70 to not less than about Shore D60. In another arrangement, the flange portion may be provided with a formation 20 which facilitates gripping engagement between the flange and the concrete structure. The formation may be of any suitable form, including perforations, dimples or some other type of recess or recesses provided in the flange or one or more protrusions on the flange such as annular ribbing on the flange. In this arrangement, the flange portion may have a pair of opposed surfaces of 25 generally planar form, the formation being on at least one of the opposed surfaces.

-4 As an alternative to providing the flange portion with a surface configured for gripping engagement with the concrete structure, the flange portion may simply be of sufficient size to extend into the concrete structure an extent which would be adequate to maintain an effective seal between the concrete and the termite 5 barrier for the purposes of providing a deterrent to entry of termites. The termite barrier may be of any suitable material such as metal or plastics material. If the material is of a type not resistant to termite attack, that portion of the termite barrier which bridges the gap between the conduit and the surrounding concrete is preferably configured so as not to present a surface on 10 which a termite can maintain a continuous physical grip. In this way, termites cannot remain in contact with said portion of the termite barrier for sufficient time to be destructive to the barrier to an extent which renders it ineffective. The invention will be better understood by reference to the following description of several specific embodiments thereof as shown in the accompanying 15 drawings in which: Figure 1 is a schematic view of a termite barrier according to a first embodiment installed about a conduit extending through a concrete slab; Figure 2 is a schematic perspective view of a termite barrier according to a second embodiment fitted onto a conduit; 20 Figure 3 is a section along line 3-3 of Figure 2; Figure 4 is a schematic perspective view of a termite barrier according to a third embodiment fitted onto a conduit; Figure 5 is a schematic view of a termite barrier according to a fourth embodiment fitted onto a conduit; 25 Figure 6 is a cross sectional view along the line 6 - 6 of Figure 5; -5 Figure 7 is a schematic view of the termite barrier of Fig 5 in one mode of installation about a conduit extending through a concrete slab; Figure 8 is schematic view of the termite barrier of Fig 5 in another mode of installation about a conduit extending through a concrete slab; 5 Figure 9 is a schematic perspective view of a termite barrier according to a fifth embodiment fitted onto a conduit; Figure 10 is a perspective view of a termite barrier according to a sixth embodiment fitted onto a conduit; Figure 11 is a cross sectional view along the line 9 - 9 of Figure 8; and 10 Figure 12 is a schematic perspective view of a termite barrier according to a seventh embodiment fitted onto a conduit. The embodiment shown in Figure 1 of the drawings corresponds to the embodiment shown in Figure 6 of Australian Patent Application 61772/94, the contents of which are incorporated herein by way of reference. 15 Referring to Figure 1, there is shown a conduit 11, such as a water or waste pipe, positioned within an opening 13 within a concrete slab 15 so as to extend through the slab. The opening 13 in the slab 15 is a potential avenue for the passage of termites into a building structure standing on the slab. A termite barrier 17 according to the first embodiment is provided to block the passage of 20 termites between the conduit 11 and the slab 15. The termite barrier 17 comprises a sheet 19 of mesh material resistant to breakdown in the environment of use and substantially resistant to termite secretions, and having a hardness of not less than about Shore D60. The pores of the mesh material have a linear dimension in any direction less than the -6 maximum linear dimension of the cross section of the head of the species of termite to be controlled. The sheet 19 of mesh material has a central aperture of lesser diameter than the external diameter of the conduit 11. Prior to pouring of the slab 15, the marginal 5 portion 21 of the sheet around the central aperture is stretched to increase the diameter of the aperture and to form a sleeve 23 to receive the conduit 11. The sleeve 23 is fitted onto the conduit 11 and clamped about the exterior thereof by clamp means 25 such as a conventional stainless steel hose clip. During the subsequent pouring of the concrete slab 15, the outer perimeter area 27 of the 10 sheet is embedded in the concrete. The outer perimeter area 27 of the sheet provides an outwardly extending flange portion 29 about the sleeve 23. Prior to setting thereof, the concrete impregnates the pores in the mesh material forming the flange portion 29 and so provides gripping engagement between the flange portion 20 of the barrier and the concrete slab 15. The gripping engagement 15 between the flange portion 29 and the concrete provides an effective termite seal therebetween. The integrity of the seal is not prejudiced by any relative movement between the conduit 11 and the concrete slab 15 arising as a result of any normal shrinkage which might occur during setting of the concrete. Further, the flexible nature of the mesh material allows that portion of the termite 20 barrier 17 which bridges the gap between the conduit 11 and the concrete slab 15 to flex to accommodate any relative movement between the conduit 11 and the concrete slab 15 without prejudicing the integrity of the seal. Referring now to Figures 2 and 3 of the drawings, the termite barrier 30 according to the second embodiment comprises a body 31 of substantially rigid 25 material such as metal or a hard plastics material. The body 31 incorporates a central sleeve 33 defining a central aperture 35 for receiving the conduit 11. An integral flange portion 37 surrounds the sleeve 33 and projects outwardly therefrom. The flange portion 37 has a pair of opposed planar faces 38.

-7 The transition region 39 between the sleeve 33 and the flange portion 37 is arcuate so as to present a convex surface 41 on the lower side. In circumstances where the material from which the body 31 is formed is not resistant to termites, the radius of curvature of the convex surface 41 is 5 sufficiently large so that it cannot be gripped by a termite. This ensures that the portion of the barrier bridging the gap between the conduit 11 and the opening in the slab through which the conduit extends cannot be degraded by attack from termites. That part of the flange portion 37 which is to be embedded in the concrete of the 10 slab incorporates a formation 43 for gripping engagement with the concrete. The formation 43 comprises a plurality of holes 45 in the flange portion into which the concrete can flow prior to setting thereof. Once the concrete has set, keying between the concrete and the flange portion 37 provided by the presence of concrete in the holes 45 ensures gripping engagement therebetween and thus 15 an effective termite seal. Referring now to Figure 4 of the drawings, the termite barrier according to the third embodiment is similar to the termite barrier according to the second embodiment and so the same reference numerals will be used to identify similar features. The third embodiment is, however, different to the second embodiment 20 in the construction of the central sleeve 33. In this embodiment, the central sleeve 33 comprises a plurality of resiliently deflectable sleeve segments 49, as shown in the drawing. The segments are formed by making radial cuts in the radially inner portion of the body 31 surrounding a central aperture. The central aperture is of lesser diameter than the external diameter of the conduit 11 and 25 so fitting of the body onto the conduit 11 causes the resilient segments to deflect laterally in the manner shown in the drawing to form the sleeve 33. With this arrangement, the resilient nature of the sleeve segments 49 are in pressure engagement with the perimeter of the conduit 11.

-8 Referring now to Figures 5 and 6 of the drawings, the termite barrier 30 according to the fourth embodiment is also similar to the termite barrier of the second embodiment and corresponding numerals are used to identify similar features. In this embodiment, however, the formation 43 provided on the flange 5 portion 37 of the body 31 comprises an annular rib 53. The annular rib is provided on one face 38 of the flange portion 37 in this embodiment, although it is certainly possible that an annular rib could be provided on both sides. The annular rib provides a key between the flange portion 37 and the concrete to ensure gripping engagement between the concrete and the flange portion. 10 Figure 7 shows the termite barrier 30 according to the fourth embodiment in one mode of installation about a conduit 11 in concrete slab 15 In this mode of installation, the flange portion 37 is embedded entirely in the concrete of the slab. Figure 8 shows the termite barrier 30 according to the fourth embodiment in 15 another mode of installation in which the flange portion 37 is only partly embedded in the concrete of the slab 15. In this mode of installation, the flange portion 37 is positioned adjacent the underside of the slab with the annular rib 53 embedded in the concrete of the slab. This arrangement serves to block the passage of termites between the conduit 11 and the concrete slab even though 20 only part of the flange portion is embedded in the concrete. Referring now to Figure 9 of the drawings, the termite barrier according to a fifth embodiment is similar to the termite barrier of the third embodiment except for the construction of the central sleeve 33. In this embodiment, the central sleeve is formed of sleeve segments 49 in a similar fashion to the central sleeve of the 25 third embodiment. In each of the embodiments described above, the flange portion 37 of the termite barrier 30 has been provided with a surface configured for gripping engagement with the concrete structure in which the termite barrier is embedded -9 so as to provide sealing therebetween against the entry of termites. In the embodiments, at least one of the surfaces 38 of the flange portion 37 has been so configured in various ways, including forming the flange portion of mesh material and providing formations which facilitate gripping engagement with the 5 concrete. There may be circumstances where it is not necessary for a surface of the flange portion 37 to be keyed to the concrete. An example of such a situation would be an arrangement where the flange portion 37 is of such a size that it can extend sufficiently into the concrete structure to an extent which would 10 maintain an adequate seal between the concrete and the termite barrier for the purposes of providing a deterrent to entry of termites. One such arrangement exists in the form of the embodiment of Figures 10 and 11 of the drawings. This embodiment is similar to the embodiment of Figures 2 and 3 except for the omission of the formation on the flange portion 37 for 15 gripping engagement with the concrete. Another such arrangement is shown in Figure 12. This embodiment is similar to the embodiment of Figures 10 and 11 except that the central sleeve 33 is formed of sleeve segments 49 similar to the arrangement shown in Figure 4. It should be appreciated that the scope of the invention is not limited to the 20 scope of the embodiments described.

Claims (3)

1. A termite barrier comprising a body having an aperture extending therethrough to sealingly receive an object therein and an outwardly extending flange portion surrounding the aperture, the flange portion being 5 adapted to be at least partly embedded in a concrete structure through which in use the object extends.

2. A termite barrier according to any one of the preceding claims wherein the flange portion has a surface configured for gripping engagement with the concrete structure in which it is in use at least partly embedded to provide 10 sealing therebetween against the entry of termites.

3. A termite barrier according to claims 1 or 2 wherein the flange portion comprises mesh material. Dated this THIRTEENTH day of JULY 1998. TERMI-MESH AUSTRALIA PTY LTD Applicant Wray & Associates Perth, Western Australia Patent Attorneys for the Applicant