AU763590B2

AU763590B2 - Termite barrier for slab penetrations

Info

Publication number: AU763590B2
Application number: AU53596/99A
Authority: AU
Inventors: Donald McGregor Ewart; John Bernard Mawson
Original assignee: GRANITGARD Pty Ltd
Current assignee: GRANITGARD Pty Ltd
Priority date: 1998-10-09
Filing date: 1999-10-11
Publication date: 2003-07-24
Anticipated expiration: 2019-10-11
Also published as: AU5359699A

Description

P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT .e an

S

I S Invention title: Termite barrier for building slab penetrations The following statement is a full description of this invention, including the best method of performing it known to us: 10509157 Title: Termite barrier for building slab penetrations Field of the invention The present invention relates to a termite barrier for building slabs and building slab penetrations. More particularly the invention relates to the protection of buildings against subterranean termite attack.

Background of the invention The need for the protection of houses and other buildings against subterranean termite attack is well known. Perhaps the most common method of protection has been to spray DDT or other insecticides on the ground immediately beneath and surrounding the building requiring protection.

However spraying the ground with insecticides having long-lasting potency can have S adverse consequences particularly about dwellings as severe allergy and other adverse reactions may result. Accordingly it is most preferable to avoid such spraying wherever S 15s possible.

It has long been known to form a concrete slab as a footing upon which a building is erected. The technique typically involves levelling the site, and digging one or more S.trenches which, when filled with concrete, form beams to strengthen the slab and to distribute the weight of the structure erected thereon across the substratum. Such beams typically extend around the perimeter of the slab and there may be one or more transverse and/or longitudinal beams depending upon the design of the desired slab and building.

Typically such strengthening beams are required below any load-bearing wall. The desired building can be erected on the upper surface of the slab after the concrete in the slab has cured to a sufficient strength.

In earlier Australian Patent Application No 15980/92 there was disclosed a sacrificial formwork for concrete comprising a plurality of panels adapted for lining the walls and optionally the base of a trench for forming a beam beneath a concrete slab. The prior application also disclosed a method for forming a concrete building slab utilising sacrificial formwork in which the walls and floor of each trench and the site below the slab are covered with a physical termite barrier.

10509157 In our Australian Patent No 673894 we disclose forming a physical termite barrier beneath a building slab by providing a substantially horizontal layer of graded aggregate between any substantially horizontal surfaces on the substratum and the underside of the slab. That application also describes the provision of a physical termite barrier between the building slab and any building slab penetrations, such as pipework or service connections.

However, it has been found that over time the substrate upon which a slab is poured can subside leaving a gap between the graded aggregate and the underside of the slab. This subsidence may be particularly pronounced in the region of a slab penetration. This is because a trench dug to receive a pipe or other service conduit which penetrates the slab is likely to be backfilled in a manner particularly prone to subsidence.

Where subsidence generates a gap between the graded aggregate and the underside of the slab, any aggregate placed in the gap between the aperture in the slab and the pipe or other conduit penetrating through the slab is liable to flow downwardly. Thus the gap may become devoid of aggregate and hence become a prime site for termite access to the building.

In our co-pending Australian Patent Application No 698397 (28459/95) we disclose methods for forming a physical termite barrier in a building aperture and a generally planar °holder for use in the methods described.

Other known prior art proposals describe the use of generally planar collars constituting a 20 termite barrier for location about a slab penetration wherein the collar is rigidly held relative to the slab penetration.

Disclosure of the invention S* The present invention accordingly provides in one embodiment a method for forming a termite barrier in a building aperture, the method including the steps of securing a holder for a termite material barrier across a building aperture, and placing a termite barrier material in the aperture whereby the termite barrier material is retained by the holder in the aperture whereby to form a termite barrier.

The present invention provides in another embodiment a method for forming a termite barrier in a building aperture, the method including the steps of securing a holder for a termite barrier material across a building aperture, and placing a termite barrier material in the aperture whereby the termite barrier material is retained by the holder in the aperture whereby to form a termite barrier, the holder including a support for retaining a termite barrier material, and an anchoring arrangement capable of bonding to a building slab to be laid about the building aperture whereby to assist securing of the position of the holder relative to the building aperture, the anchoring arrangement comprising a plurality of vertically spaced anchoring members extending outwardly from the support.

The present invention provides in another embodiment a holder capable of use in methods of the invention, the holder including a support for retaining a termite barrier material, the holder including a support comprising a collar for retaining a termite barrier material in the building aperture relative to a slab penetration, the inner surface of the collar being spaced from the outer surface of the slab penetration whereby to define a gap for receipt of a termite barrier material.

In this embodiment, the internal dimension of the holder is greater than the outer dimension of the slab penetration, the gap providing a location for placement of termite barrier material so as to prevent the ingress of termites at the site of the slab penetration.

The gap between an inner surface of the holder and an outer surface of the slab penetration is preferably in the range of about 5 to 30mm, and more preferably from about 20 to The present invention provides in another embodiment a holder capable of use in methods of the invention, the holder including a support such as a collar for retaining a termite *20 barrier material, and an anchoring arrangement capable of bonding to a building slab to be laid about the building aperture whereby to assist securing of the position of the holder relative to the building aperture, the anchoring arrangement comprising a plurality of vertically spaced anchoring members extending outwardly from the support.

*aa a.

The term slab penetration is used in relation to the present invention to include any pipework, conduit or service connection provided for a building and extending in building slab, such as plumbing, gas and electricity connections.

The term building aperture is used in relation to the present invention to include any opening extending through a slab or wall of a building. The term building aperture as used herein therefore includes any gap or void between a slab and a slab penetration, any gap or void between two slabs, such as in the case of construction joints, and any weep hole or ventilation slit extending through a wall or floor of a building.

A termite barrier material according to the invention may be any barrier material which has the quality of being impervious or substantially impervious, and/or a deterrent, to termites.

Most preferably the termite barrier material is selected so that the integrity of the termite barrier as a barrier to termites is not affected by environmental or physical changes in the region of the slab penetration, such as differential movement between the slab penetration, the building slab and the building slab foundation.

The termite barrier material is preferably formed from a material which retains a degree of flexibility in response to forces applied to the material following placement of the material in a holder according to the invention. The arrangement is preferably such that the termite barrier material is sufficiently flexible to absorb anticipated differential movement between the slab penetration, the building slab and the building slab foundation whilst maintaining the integrity of the termite barrier.

The termite barrier material may be a fluid. The fluid may be a liquid or a gas, or a combination of these. The fluid may comprise a medium capable of carrying a deterrent o for termites, such as a pesticide or termite-foraging deterrent agent.

In one embodiment the termite barrier material comprises a liquid capable of resisting penetration by termites. The liquid is preferably of sufficient viscosity so as to be retained by the holder when placed in the holder such that it does not flow out of the holder to any significant extent. The liquid may carry a deterrent for termites, such as a pesticide or 20 termite-foraging deterrent agent.

In another embodiment the termite barrier material comprises a solid. In this embodiment the termite barrier material may comprise a mesh. The mesh is preferably selected so as to be resistant to termite attack. The mesh may be formed from a metallic material, such as a steel. One mesh suitable for use in accordance with the present invention is marketed under the trade mark Termi-Mesh. Other solid materials are envisaged for use as a termite barrier material within the scope of the present invention.

The termite barrier material may comprise a web. The web may be impregnated or otherwise treated with a pesticide or termite-foraging deterrent agent. The web may comprise a sheet. The sheet may be substantially planar. The sheet may comprise a synthetic material. One material suitable for use as a web in accordance with the present invention is marketed under the trade mark Kordon TMB. The Kordon TMB product comprises two sheets of a plastic material which sandwich a termiticide-impregnated fibrous web. Other webs are envisaged for use as a termite barrier material within the scope of the present invention.

In another embodiment a termite barrier material according to the invention comprises a termite deterrent such as a pesticide or termite-foraging deterrent agent.

In another embodiment a termite barrier material according to the invention comprises a particulate material. Suitable particulate materials include glass particles, sand, shredded mesh, sawdust and fibrous materials resistant to attack from termites. The particulate material may be impregnated or otherwise treated with a termite deterrent such as a pesticide or termite-foraging deterrent agent.

The particulate material is preferably graded and/or to facilitate packing or fitting and to minimise interstices. Most preferably the particulate material is graded for size, shape, density and composition. Other particulate materials are envisaged for use as termite barrier material in accordance with the invention.

In another embodiment the termite barrier material comprises a termite resistant expandable foam. The arrangement is preferably such that a foam material placed in the holder expands to a sufficient extent so as to fill any gap between the holder and the slab penetration whereby to create a barrier to termites. One expandable foam suitable for use as a termite barrier material is formed from polyurethane. Other expandable foam materials are envisaged for use as a termite barrier material in accordance with the 20 invention.

In another embodiment, the termite barrier comprises a suitable stone type. In one preferred embodiment, the termite barrier material includes a layer of graded aggregate.

The particles of graded aggregate may be impregnated or otherwise treated with a pesticide or termite-foraging deterrent agent.

The graded aggregate used in accordance with the present invention is preferably a graded granite aggregate and most preferably a graded granite aggregate which has received National Accreditation from the Australian Building Control Board (or equivalent).

One product suitable for use as a graded stone aggregate in accordance with the present invention is marketed under the trade mark Granitgard.

Most preferably the graded aggregate used in accordance with the present invention comprises graded stone screenings having a dimension generally in the range of 1.13 to and more preferably in the range of from 1.18 to 3.15mm. The aggregate is preferably graded to facilitate packing or fitting and to minimise interstices. Most preferably the aggregate is graded for size, shape and composition.

A holder according to the present invention may be provided with replenishment means whereby to replenish the gap or void between the slab penetration and the holder with fresh termite barrier material should the gap or void become depleted, and/or with a supplementary termite deterrent such as a pesticide or termite-foraging deterrent agent.

The replenishment means may take any suitable form. In one embodiment the replenishment means comprises a tube having an inlet and an outlet, the outlet being in fluid communication with the gap or void. Other replenishment means are envisaged within the scope of the present invention.

A termite barrier according to the present invention may be retained by the holder in a number of ways. In one embodiment, the termite barrier material may be retained by placing the material on the holder whereby the material is retained from beneath by the S 15 holder. Other retaining arrangements and holder orientations are envisaged within the scope of the present invention.

A termite barrier material according to the present invention may be laid directly into a S. building aperture formed with the holder in place to retain the termite barrier material. A termite barrier material in the form of a particulate material or an aggregate layer may be lightly compacted in the aperture.

In one preferred embodiment, a termite barrier material in accordance with the invention may substantially fill the building aperture and be compacted to ensure complete contact with the adjoining slab penetration or building aperture surrounding the slab penetration.

In an alternative embodiment, a termite barrier material in accordance with the present invention may be installed in the building aperture to a minimum depth of about In another preferred arrangement according to the present invention a termite barrier for a building is provided by ensuring that any building apertures are provided with a holder according to the present invention, the holder retaining a termite barrier material within the building aperture.

A holder according to the present invention may be of any type which is capable of retaining a termite barrier material within a building aperture. Preferably the holder is 7 capable of being positioned in or about a building aperture formed adjacent a slab penetration or adjoining slab. The holder preferably fully surrounds the perimeter of the slab penetration, whereby the holder is capable of retaining the termite barrier material in proximity to the perimeter surface of the adjoining slab or slab penetration. This construction may be adapted to maintain contact between the termite barrier material and the perimeter surface of the slab penetration or an adjoining slab, preventing possible pathways for termites from forming in the building aperture between the slab and the slab penetration.

The holder may be suitably positioned across, in or adjacent the proposed building aperture prior to laying the building slab.

The holder is preferably positioned between the substratum and the slab prior to laying the slab whereby the holder becomes embedded in the slab to some degree when the slab is laid and thereby positioned to support a termite barrier material placed thereon and thereby retain the termite barrier material within the building aperture. Preferably the holder becomes at least partially embedded in the laid slab.

The holder may be apertured to facilitate positioning of the holder adjacent and preferably substantially surrounding a slab penetration. The internal diameter or width of the holder aperture is preferably slightly larger than the perimeter dimension of the slab penetration whereby to enable the holder to be positioned around the perimeter of the slab penetration.

20 The shape of the holder is suitably adapted to conform with the cross-sectional shape of the building aperture or slab penetration.

In one embodiment of the invention, the construction and arrangement may be such that there is minimal clearance between the holder aperture and the slab penetration, whereby the clearance between a termite barrier material retained by the holder and the slab penetration does not allow for the escape of the termite barrier material. In one preferred arrangement the holder is capable of engaging with the slab penetration. Accordingly the holder may include an engaging arrangement. The engaging arrangement may be formed about an aperture in the holder. The engaging arrangement is preferably such that sealing engagement with a perimeter surface of the slab penetration results. The area of engagement is preferably sufficiently flexible to permit a degree of relative movement between the holder and the slab penetration. The arrangement is preferably also such that abrading of the slab penetration does not occur to any appreciable extent as a result of any relative movement between the holder and the slab penetration.

The holder may engage the slab penetration in one or more of a number of ways. The holder aperture may include one or more fingers to engage the surface of the slab penetration. The aperture may include a web. The aperture may be flanged. The holder may in one embodiment be adhered to the slab penetration at any point of contact with the slab penetration.

In one preferred embodiment, the holder comprises a grate. The grate may be of a substantially planar construction. For example, the holder may comprise a substantially planar sheet of a mesh material. The pore dimension of the interstices of the mesh sheet may be selected so as to be less than the average minimum dimension of particles of termite barrier material, in an embodiment where the barrier material comprises a particulate material, to be retained by the holder. The pore dimension may in one preferred embodiment be at least 0.5mm, and more preferably in the range of from 1.5 to 2mm.

15 In an alternative arrangement in accordance with the present invention the holder comprises a substantially planar sheet of material impervious or substantially impervious to the termite barrier material and/or to termites. One such material may include unplasticised PVC.

In another embodiment, a holder according to the present invention comprises a collar.

S 20 The collar may be capable of being positioned adjacent the perimeter surface of the slab penetration.

In another embodiment, a holder according to the present invention comprises an apertured cup.

In another embodiment, a holder according to the present invention comprises a container.

The container may be in the form of a trough. The trough may be substantially U-shaped.

The trough may run across, parallel to, beneath or alongside a building aperture, such as a construction joint. In one preferred embodiment of this arrangement, the holder comprises a substantially U-shaped trough filled with a termite barrier material retained by the holder beneath a construction joint. The trough may include one or more lugs capable of bonding to the slab to be laid. The arrangement may be such that at least one lug is positioned such that it will become partially embedded in one slab, whilst at least one other lug is positioned such that it will become at least partially embedded in an adjacent slab, on casting of the slabs. A trench may be dug at the site of the proposed construction joint prior to laying abutting slabs whereby to locate the trough relative to the construction joint.

The trough is then positioned in the trench and filled with a termite barrier material. When the abutting slabs are cast the lugs of the trough become at least partially embedded in adjacent slabs whereby to secure the holder across the building aperture between abutting slabs and thereby to form a termite barrier for the construction joint. The arrangement may be such that the layer of graded aggregate held by the trough extends a minimum of approximately 50mm in each direction from an edge of the slab.

A holder according to the present invention may be at least partially lined with a cushioning material. The cushioning material may comprise a felt, such as a lubricated felt.

In a further embodiment, a holder according to the present invention comprises a cage.

The cage may be capable of being positioned in the building aperture formed adjacent to 15 the slab penetration.

In one embodiment of this arrangement, the holder is generally in the shape of the building aperture formed adjacent the slab penetration across which the holder is to be positioned.

For example, where the slab penetration is substantially circular, the gap or void formed around the slab penetration may also be substantially circular, whereby the holder may •20 comprise a substantially cylindrical sleeve capable of being positioned in the gap or void and extending about or around at least part of the perimeter of the slab penetration.

Other holder shapes and constructions are also envisaged within the scope of the present invention. These may include, for example, a disc, or a flange. The disc or flange may be substantially circular.

A holder according to the present invention is preferably capable of being anchored to the building slab. Accordingly the holder may include an anchoring arrangement. The anchoring arrangement may be installed so as to form a termite resistant bond between the holder and a building slab. The anchoring arrangement may assist the holder to maintain its position relative to the building aperture, or relative to the building slab and a slab penetration. The anchoring arrangement may be constructed and arranged whereby to allow for a degree of independent movement between the slab and slab penetration or within the building aperture. The anchoring arrangement may be capable of bonding to the slab to be laid. In one embodiment, the anchoring arrangement comprises one or more ridges, wings or lugs. The ridges, wings or lugs may be disposed on the holder, and/or about the periphery of the holder. The wings may be upturned or outwardly extending.

This arrangement has been found to assist bonding of the holder to the slab.

In one embodiment of this arrangement a holder according to the present invention comprises a substantially planar web of mesh material with a plurality of peripheral sections upturned to form wings extending out of the plane of the web. The arrangement is preferably such that the holder may be laid on the substratum upon which a slab is to be poured such that after pouring and curing, also sometimes known as casting, the web of the holder is substantially flush with the underside of the slab and the wings are embedded in the slab.

Other anchoring arrangements are envisaged within the scope of the present invention.

A holder according to the invention may be formed from one or more components. If the holder is formed from one component, the holder is preferably apertured to a dimension 15 larger than the width of a slab penetration.

This arrangement enables the holder to be slipped over a slab penetration and positioned relative to the penetration whereby to retain the termite barrier material in the gap or void adjacent the penetration. The holder aperture is preferably located on a central axis of the holder.

20 A holder comprising two or more components can be used to retain the termite barrier S"material in the building aperture whilst providing for a degree of independent movement of the components of the holder.

"If the holder is formed from a number of components, the components of the holder are preferably constructed and arranged such that when assembled an aperture in the holder is defined which is larger than the perimeter dimension of the slab penetration. This arrangement enables the holder to be positioned in the gap or void adjacent the slab penetration.

A holder according to the invention may be fabricated from any suitable material.

Examples of suitable fabrication materials include sheet or mesh materials, metal, stainless steel, stainless steel mesh, plastics materials, flexible rubberised compounds, fabric materials, fibrous materials, scourer-type materials, including those formed from loose matrices of abrasive fibres coated with a plastics material, and polythene, unplasticised PVC, or neoprene. Other fabrication materials suitable for a holder according to the invention include those which retain moisture and do not allow it to seep through either from or to the substratum to any appreciable extent.

Other materials for fabricating the holder are also envisaged within the scope of the present invention. Most preferably the holder is formed from a termite resistant material. The design of the holder may make it less susceptible to termite attack, for example by utilising smooth surfaces, or rounded angles or joints.

A holder according to the invention does not necessarily function as a termite barrier. If for example the holder comprises a mesh sheet, the interstices of the sheet may be selected so as to act as a barrier to impede the progress of termites. The material selected may be such that it is capable of preventing termites chewing through the material. One such suitable material comprises a stainless steel mesh, marketed under the trade mark Termi- Mesh. It is also envisaged within the scope of the present invention that the interstices of 15 the mesh are larger than the size required to act as a termite barrier. The interstices of the *o mesh should however be of a dimension suitable for retaining particulate materials within the building aperture to act as a termite barrier.

In another embodiment, a holder according to the invention includes a support for retaining a termite barrier material, and an anchoring arrangement capable of bonding to a building slab to be laid about the building aperture whereby to assist securing of the position of the holder relative to the building aperture, the anchoring arrangement comprising a plurality of vertically spaced anchoring members extending outwardly from the support.

In this embodiment, the support comprises a collar. The collar may be elongated. The S•collar may be tubular. In a preferred embodiment the collar comprises an elongated tube capable of surrounding at least part of a slab penetration in the form of a pipe when positioned adjacent the slab penetration.

In a preferred embodiment there is no intimate contact between the rigid holder structure and the slab penetration, the only contact being between the slab penetration and the termite barrier material. As a consequence the integrity of the termite barrier so formed will not be adversely affected by environmental or physical changes in the region of the slab penetration, such as differential movement between the slab penetration, the building slab when laid and the building slab foundation.

In this embodiment the inner surface of the collar is preferably in use spaced from an outer surface of the slab penetration whereby to define a gap or void between the collar and the slab penetration in which a termite barrier material can be received.

An anchoring arrangement comprising vertically spaced anchoring members according to the invention may take any suitable form. Preferably the anchoring member is capable of bonding to the slab when laid. An anchoring member may comprise a flange, ridge, wing or lug. The flange, ridge, wing or lug may be disposed on the support, and/or around the periphery of the support. The flange, ridge, wing or lug may extend partly or fully around the periphery of the support. The flange, ridge, wing or lug may be substantially horizontal. It may be disposed at an angle to the horizontal. The flange, ridge, wing or lug may be upturned, downturned or outwardly extending from the support. Other anchoring members are envisaged for use as anchoring arrangements within the scope of the present S. invention.

An anchoring member according to the invention may be of a different size and/or shape to 15 another anchoring member provided on the support. In one embodiment one anchoring member extends further outwardly from the support than does another anchoring member.

In another embodiment, one of the anchoring members may be upwardly and outwardly extending to a greater degree than another anchoring member.

Vertical spacing of anchoring members according to the invention may be achieved by 20 providing a spiral flange, ridge, wing or lug on the outer surface of the support.

In one particularly preferred embodiment a pair of vertically spaced upwardly and outwardly extending anchoring members are provided on an outer face of the support in the form of an elongated collar.

In one particularly preferred embodiment comprising a pair of vertically spaced outwardly extending anchoring members arranged on the support, the lower one of the pair extends further outwardly than the upper one of the pair.

A holder according to the invention may comprise a base. The base may be adapted to seat on a moisture barrier provided for the building slab. The base may take any suitable form.

In one embodiment the base comprises an outwardly extending flange extending at least partly around the periphery of the support in the region of the base of the support. In another embodiment the base may comprise a plurality of discrete feet extending outwardly from the support in the region of the base of the support.

A holder according to the invention may be provided with one or more retaining disks. A retaining disk may be provided in the interior of the support for the purpose of retaining the termite barrier material in the gap or void around the periphery of the slab penetration when the holder is positioned in the aperture adjacent the slab penetration and to prevent egress of the barrier material from the gap or void. The disk does not need to be termite resistant although it is preferably formed from a material which is not attractive to termites or is otherwise difficult for termites to chew through. The disk may accordingly be formed from any suitable material, such as a synthetic plastics or polymeric material. The material selected may be impregnated or otherwise treated with a pesticide or termite-foraging deterrent agent.

A retaining disk is preferably provided at least at the base of the holder prior to placing the termite barrier material in the gap or void. In this embodiment an inner face of the holder in the region of the base of the holder may be provided with an inwardly extending lip whereby to seat the retaining disk. A top retaining disk may be provided following placement of the termite barrier material in the gap or void. A retaining disk according to the invention may be secured to the holder in any suitable manner, such as by adhesion or "-by mere gravity.

A building aperture according to the present invention is preferably formed around at least part of the perimeter of the slab penetration. The building aperture preferably forms an annulus around the slab penetration whereby the building aperture extends fully around the perimeter of the slab penetration. The building aperture may be of a cross-sectional shape which substantially conforms to the cross-sectional shape of the slab penetration, but of larger width or diameter than that of the width or diameter of the slab penetration.

In another arrangement according to the present invention, a building aperture in the form of a cavity may be formed within the walls of the building. A holder according to the invention may be positioned adjacent to or within any weep hole in the wall of the building so as to retain a termite barrier material placed in the cavity defined between the inner and outer walls, for example. A weep hole opening is preferably covered by a durable material. The durable cover may be secured within the weep hole. The material selected may also be capable of resisting corrosion, termite attack or damage by rodents, and allowing the free passage of air and water.

Formwork in the form of a collar may be placed around the slab penetration prior to the slab being laid whereby to assist in forming a building aperture in the form of a gap or void around the penetration after the slab has been laid. When the slab has set for a time which is sufficient such that any substantial movement of the slab is unlikely to occur, the formwork may be removed from around the penetration. If not embedded in the slab or otherwise positioned the holder may be positioned to retain the termite barrier material, such as a graded stone aggregate. The graded stone aggregate may be installed in the building aperture whereby to form a termite barrier.

In one particularly preferred arrangement according to the present invention a building aperture in the form of a gap or void is formed in a building slab by preparing a substratum on which the slab is to be laid, excavating for a building slab penetration, fixing the desired position of the slab penetration with respect to the slab to be laid, positioning a holder according to the present invention to be formed around at least part of the perimeter of the slab penetration, providing a formwork about the slab penetration, laying the slab and curing it for a sufficient time whereby to form a building aperture, and retaining a termite barrier material in said aperture by said holder, whereby to form a termite barrier.

The present invention provides in a particularly preferred embodiment a method for forming a termite barrier in a building aperture, the method including the steps of securing a holder for a termite barrier material across a building aperture, and placing a termite barrier material in the aperture whereby the termite barrier material is retained by the 0holder in the aperture whereby to form a termite barrier, the holder including a support in the form of an elongated tubular collar for retaining a termite barrier material relative to a slab penetration positioned in the aperture, the inner surface of the collar being spaced from the outer surface of the slab penetration, and an anchoring arrangement capable of bonding to a building slab to be laid about the building aperture whereby to assist securing of the position of the holder relative to the building aperture, the anchoring arrangement comprising at least one anchoring member extending outwardly from an outer surface of the collar.

Brief description of the drawings To further assist in the understanding of the present invention, particularly preferred embodiments of the invention will now be described in relation to the accompanying drawings.

In the drawings, in which like features are given like numerals: Figure 1 is a cross sectional view of a typical building construction arrangement according to one embodiment of the present invention, Figure 1 a shows an enlarged view of the circled area of Figure 1, Figure 2 is a perspective view of a typical holder according to one embodiment of the present invention, Figure 2a is a perspective view of a typical holder according to a further embodiment of •the present invention, and Figure 3 is a perspective view of the holder of Figure 2 partially in section.

Detailed description of the preferred embodiments Turning to the drawings, Figure 1 shows a building slab 1 of conventional form including a capping layer 2 and an edge beam 3. Slab 1 includes an upper surface 4 which generally forms the floor of a building erected on slab 1. Edge beam 3 of slab 1 includes a step or rebate 5 of conventional form adapted for receiving an outer brick wall 6. Inner lining wall 0S*@ 7 is erected on upper surface 4 of slab 1. The slab 1 is laid directly over the prepared 20 substratum 9 such that the lower surface 8 of slab 1 abuts the upper surface of the o• substratum 9. A vapour membrane (not shown) may be interposed between the prepared oooo substratum 9 and the slab 1 prior to laying of the slab 1.

S

Slab penetrations 10 and 11 are provided through slab 1 via building apertures in the form of gaps or voids 16 and 17 respectively. The slab penetrations may be plumbing or other service connections, and may be suitably lagged as shown at 22. Prior to laying of the slab 1, the site of the slab penetration is determined, and formwork which may take the term of the holder 14 by itself or in association with additional forming material is positioned to define a building aperture adjacent the slab penetration. Where the holder represents the formwork of itself it should extend the full length of the building aperture formed in the slab.

Holder 14 includes upturned corners or wings 24 at the perimeter of the holder 14. Wings 24 are capable of bonding to and/or being embedded in slab 1 and retaining the position and orientation of holder 14 with respect to the slab penetration 10, on laying of the slab 1.

A removable collar (not shown) fabricated from polystyrene or other suitable material such as metal or foam can be positioned around the slab penetration 10 generally in the longitudinal direction of the penetration 10 between the tubular collar 23 of the holder 14 and the slab penetration 10. This serves to locate the holder in position when concrete is poured so that the holder acts as a former for the concrete. The removable collar is removed after concrete slab 1 is cured.

Holders 14 are shown in Figure 1 in position adjacent the slab penetrations 10 and 11 respectively. In the embodiment shown in Figure 1, holder 14 is interposed between substratum 9 and slab 1 with vertically spaced anchoring members being embedded in slab 1. The apertured holder 14 is preferably positioned in the vicinity of the intended building aperture 16 prior to laying of the slab 1 by slipping the holder over the slab penetration to the upper surface of substratum 9.

"A slab penetration in the form of an electrical conduit 20 includes a layer 21 of particulate termite barrier material placed in the cavity between inner wall 7 and outer brick wall 6. In the embodiment shown, conduit 20 does not include a holder, however it will be appreciated that a suitable holder 14 can be positioned if necessary around the juncture of 20 the conduit 20 with edge beam 3.

A termite barrier material in the form of a layer of particulate termite barrier material 18 is placed in holders 14 in building apertures 16 and 17 to provide a termite barrier. The S•provision of a holder as described for the termite barrier material prevents to any significant extent the displacement of termite barrier material from a region in close 25 proximity to the pipe 10 as a result of relative movement of the slab or substratum with respect to the pipe Figures 2 and 3 show a typical holder 14 for use in the methods described herein. Holder 14 is adapted to be positioned between the capping layer or upper edge 2 of the slab and the lower edge 2a of the slab.

It will be seen that holder 14 includes a central aperture of a dimension larger than the perimeter dimension of the slab penetration in the form of pipework 10 so as to maintain a gap between the holder 14 and the pipework 10 whereby there is no intimate contact between the rigid structure of the holder 14 and the pipe Holder 14 is capable of retaining a termite barrier material placed in the gap between a slab penetration in the form of pipework 10 and the holder 14 indicated by arrow B. The gap indicated by arrow B is filled with a termite barrier material of any suitable form as described herein.

Holder 14 in the embodiment shown includes an elongated tubular collar 23, a pair of vertically spaced anchoring members 24 and 25, and an outwardly extending base 26.

As will be seen from Figures 2 and 3, anchoring members 24 and 25 are upwardly turned and outwardly extending. It will also will noted that lower anchoring member 25 of the pair is of larger dimension than upper anchoring member 24. In Figure @a a similar holder is shown, the only difference being that the anchoring members 24, 25 are not turned upwardly.

Retaining disk 27 is placed in the gap or void defined around the pipework 10 in the S 15 direction indicated by arrow A to retain a termite barrier material in the gap or void oooo following placement of the termite barrier material in the gap or void.

An inner face of the holder 14 in the region of the base of the holder is provided with an inwardly extending lip 28 whereby to seat a lower retaining disk 29 loosely fitted around the pipe and placed in the gap or void. The retaining disk is constructed to seal off the gap 20 between the pipework 10 and collar 23 to create an annular retaining region there between **for holding the termite barrier material 30. The barrier material may take the form of a graded aggregate.

In use, with reference to Figure 1 substratum 9 is prepared on which a concrete slab 1 is to S°be laid, including excavation for one or more slab penetrations. A holder according to the invention is laid on the substratum 9 around the perimeter of the slab penetration, and either adhered to or engaged with the slab penetration so that it does not move during the concrete pour. A removable collar (not shown) is placed over the slab penetration such as pipework in the gap between the pipework and the collar 14 to hold the collar in place, whereupon the final position of the slab penetration is fixed with the collar 14 acting as former for the concrete. The slab 1 is laid and cured, and the removable collar is removed.

A layer of a termite barrier material such as, for example, a graded stone aggregate is 18 placed in the building aperture formed around the slab penetration to a minimum depth of approximately 75mm. The termite barrier material may then be compacted.

Alternatively a lower retaining disk may be placed in the collar 14 to seat against the extending lip 28. Termite barrier material may then be placed in the gap between the tubular collar 23 and the pipework and compacted after which an annular retaining disk 27 is applied to sit on top of the compacted barrier material. The combination of retaining disks and barrier material can have the effect of locating and holding the collar 14 during the concrete pour instead of the removable collar described above.

The holder provided by the present invention is capable of being readily installed to prevent termite access and maintain the integrity of the termite barrier material with respect to a building aperture even if there is relative movement between the aperture and the ground or other facilities such as a pipe, wire or conduit..

A building may thus be protected from termite attack by the provision in any building aperture of a termite barrier material retained by a holder according to the present invention.

While it has been convenient to describe the invention herein in relation to particularly preferred embodiments, it is to be appreciated that other constructions and arrangements are also considered as falling within the scope of the invention. Various modifications, alterations, variations and/or additions to the constructions and arrangements described 20 herein are also considered as falling within the ambit and scope of the present invention.

The word 'comprising' or forms of the word 'comprising' as used in this description and in the claims do not limit the invention claimed to exclude any variants or additions.

Claims

2. The method according to claim 1, wherein said collar comprises an elongated tube.
3. The method according to either claim 1 or claim 2, wherein the interior of the collar is sufficiently wide so as to provide a gap for receipt of a termite barrier material between an inner surface of the collar and an outer surface of a slab penetration extending through the aperture.
4. The method according to any one of claims 1 to 3, wherein said vertically spaced anchoring members comprise flanges, ridges, wings or lugs °ooo disposed about the periphery of said support and capable of extending into and bonding with said slab when laid. S 25 5. The method according to claim 4, wherein one or more of said flanges, :ridges, wings or lugs extends outwardly and upwardly.
6. The method according to any one of the preceding claims, wherein at least one of said flanges, ridges, wings or lugs extends around substantially the whole of the perimeter of the support. S 30 7. The method according to any one of claims 1 to 3, wherein the anchoring arrangement comprises a pair of vertically spaced flanges extending upwardly and outwardly from said support, each of said flanges extending around the whole of the perimeter of said support, the lower one of said S: flanges further outwardly than the upper of one of said flanges.
8. The method according to any one of the preceding claims, wherein said holder is cast in a slab and acts as a former for the building aperture and the building aperture is formed in the slab or between adjoining slabs.
9. The method according to any one of the preceding claims, wherein the termite barrier material comprises any one or more of a liquid capable of resisting penetration by termites, a mesh, web, pesticide, termite foraging deterrent agent, particulate material, termite resistant expandable foam, graded stone or graded aggregate. The method according to claim 9, wherein the termite barrier material 1o comprises graded stone screenings having a dimension generally in the range of from about 1.18 to 3.15 mm.
11. The method according to claim 10, wherein the termite barrier material is a graded granite aggregate having a dimension generally in the range 1.18 to 3.15 mm.
12. The method according to any one of the preceding claims, wherein the aperture is filled with termite barrier material to a minimum depth of about mm.
13. The method according to any one of the preceding claims, wherein the holder is positioned in and extends substantially the length of a building aperture in a slab, (ii) the holder is arranged to surround a slab penetration and is spaced therefrom to leave a gap between the holder and the slab penetration, and (iii) the termite barrier material is held in the gap in such a manner as to S 25 allow relative movement between the holder and the slab penetration :whilst maintaining the integrity of the termite barrier.
14. The method according to any one of the preceding claims, wherein the collar comprises an inwardly extending lip and wherein the method further comprises seating a lower retaining disk on the lip prior to placing said termite barrier material in said aperture whereby the lower retaining disk and lip form a retaining region for holding said termite barrier material. .0.0 o ooo o0.0O 0 The method according to any one of the preceding claims, further comprising the step of positioning a top retaining disk over an upper surface of said termite barrier material following the placement of said termite barrier material in said aperture.
16. A method for forming a termite barrier in a building aperture according to claim 1 substantially as hereinbefore described and with reference to any one of the accompanying drawings.
17. A holder for forming a termite barrier in a building aperture according to the method in any one of the preceding claims, said holder comprising a collar for retaining a termite barrier material in a building aperture, the interior of the collar being sufficiently wide so as to provide a gap for receipt of a termite barrier material between an inner surface of the collar and an outer surface of a slab penetration extending through the aperture, the collar comprising a support having an anchoring arrangement for maintaining the position of the holder relative to the building aperture, the anchoring arrangement comprising a plurality of vertically spaced anchoring members extending outwardly from said support and capable of bonding to the slab when laid.
18. The holder according to claim 17, wherein said collar comprises an elongated tube.
19. The holder according to either of claims 17 or 18, wherein said anchoring members comprise flanges, ridges, wings or lugs disposed about the periphery of said support.
20. The holder according to claim 19, wherein one or more of said flanges, 25 ridges, wings or lugs extends outwardly and upwardly.
21. The holder according to either claim 19 or claim 20, wherein at least one of the flanges, ridges, wings or lugs extends around substantially the whole of the perimeter of the support.
22. The holder according to either of claims 17 or 18, wherein the anchoring arrangement comprises a pair of vertically spaced flanges extending upwardly and outwardly from said support, each of said flanges extending around the whole of the perimeter of said support, the lower one of said flanges further outwardly than the upper of one of said flanges.
23. The holder according to any one of claims 17 to 22, wherein the collar comprises an inwardly extending lip and wherein a lower retaining disk is seatable on the lip whereby the lower retaining disk and lip form a retaining region for holding termite barrier material.
24. The holder according to any one of claims 17 to 23, and further comprising a base having an outwardly extending flange. The holder according to any one of claims 17 to 24, substantially as hereinbefore described and with reference to any one of the accompanying drawings. Granitgard Pty Ltd 22 May 2003 *O~ go eeo **g