AU777086B2 - Improvements in or relating to termite barriers - Google Patents

Description

P/00/0I11 Rcgulation 3.2

AUSTRALIA

Patents Act 1990 ORI GINAL COMPLETE SPECIFICATION STANDARD PATENT Invention title: IMPROVEMENTS IN OR RELATING TO TERMITE BARRIERS The following statement is a full description of this invention, including the best method of performing it known to us: IMPROVEMENTS IN OR RELATING TO TERMITE BARRIERS Field of invention The present invention relates to a termite barrier for the protection of buildings against subterranean termite attack. More particularly the invention relates to a termite barrier to protect building apertures, building slabs and building slab penetrations.

Background to the invention In this specification, where a document, act or item of knowledge is referred to or discussed, this reference or discussion is not an admission that the document, act or item of knowledge or any combination thereof was at the priority date: 10 part of common general knowledge; or (ii) known to be relevant to an attempt to solve any problem with which this specification is concerned.

The need for the protection of houses and other buildings against subterranean termite attack in certain climates 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 uncontrolled spraying, and spraying the ground with insecticides having S long-lasting potency can have adverse consequences particularly about dwellings as severe allergy and other adverse reactions may result. Accordingly it is most preferable to avoid 20 such spraying wherever possible.

Physical termite barriers have been proposed as alternatives to spraying. These include mesh, webs, particulates and graded stone aggregates.

An example of a graded aggregate termite barrier is described in Australian Patent No 673894. This involves 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 patent also describes the provision of a physical termite barrier between the building slab and any building slab penetrations, such as pipework or service connections.

It has been observed by the Applicant that over time the ground upon which a building slab is poured can subside. 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 termite barrier material and the slab, a prime site for termite access to the building is formed.

In Applicant's Australian Patent No 698397 (28459/95) methods are disclosed for forming a physical termite barrier in a building aperture and a generally planar holder for use in the methods described in that specification.

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

Summary of Invention The term "slab penetration" as used in this description and in the claims includes any pipework, conduit or service connection extending through a building slab to provide access to a building, such as plumbing, gas and electricity connections.

The term "building aperture" as used in this description and in the claims includes any opening in a slab or wall of a building, including 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, any gap or void between a slab and masonry, and any weep hole or ventilation slit extending through a wall or floor of a building.

S. According to one aspect, the present invention provides a termite barrier for a building aperture, the barrier including a termite barrier material held by an at least partly i 15 sacrificial element, the arrangement being such that on sacrifice of at least part of the :":element the termite barrier material is activated to form a termite barrier for the aperture.

The present invention provides in another separate embodiment a termite barrier for a building aperture, the barrier including particles of a termite barrier material held in a cluster by an at least partly sacrificial element, the arrangement being such that on sacrifice of at least part of the element the termite barrier material is released into the aperture to form a termite barrier for the aperture.

The present invention provides in another separate embodiment a method for forming a termite barrier in a building aperture, the method including the steps of placing an at least partly sacrificial element across a building aperture, the sacrificial element holding a termite barrier material, and activating the termite barrier material by sacrifice of at least part of the element, whereby to form a termite barrier in the aperture.

The present invention provides in another separate embodiment a method for forming a termite barrier in a building aperture, the method including the steps of placing an at least partly sacrificial element across a building aperture, the sacrificial element holding particles of a termite barrier material in a cluster, and releasing the termite barrier sujm 10676419 material into the aperture by sacrifice of at least part of the element, whereby to form a termite barrier in the aperture.

The step of placing the at least partly sacrificial element across the building aperture may include the step of securing the element across the aperture.

The present invention provides in another separate embodiment a method for forming a building slab having a termite barrier in a building aperture formed therein, the method including the steps of preparing a substratum on which a slab is to be laid, excavating for a slab penetration, placing a formwork around the slab penetration to define a building aperture around the penetration, the formwork comprising an at least partly sacrificial element with which a termite barrier material is held, pouring concrete for forming the slab, and after a suitable period sacrificing at least part of the formwork whereupon the termite barrier material is released into the aperture, whereby to form a building slab having a termite barrier in the aperture.

The present invention provides in another separate embodiment a method for forming a building slab having a termite barrier for ajoint formed therein or about a perimeter thereof, the joint forming a building aperture, the method including the steps of preparing a substratum on which a slab is to be laid, placing a formwork along a proposed joint for forming the aperture, the formwork comprising an at least partly sacrificial element with which a termite barrier material is held, pouring concrete for forming the slab, and after a suitable period sacrificing at least part of the formwork whereupon the termite barrier material is released into the aperture, whereby to form a building slab .oo.

having a termite barrier in the aperture.

A building aperture according to the present invention is preferably formed around at least part of the perimeter of a 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. An at least partly sujm 10676419 sacrificial element according to the invention may be positioned adjacent to, within or alongside any building aperture in the wall of the building so as to retain a termite barrier material for release into the cavity defined between the inner and outer walls, for example.

A building aperture in the form of 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.

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.

termite barrier material is preferably formed from a material which retains a 15 degree of flexibility in response to forces applied to the material following placement of the material in a building aperture according to the invention. The arrangement is preferably such that the termite barrier material is sufficiently flexible to absorb anticipated differential movement between a slab penetration, a building slab and another adjoining slab, masonry adjoining the edge of the slab or building slab foundation whilst maintaining 20 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 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 in the building aperture such that it does not flow out of the aperture to any significant extent. The liquid may carry a deterrent for termites, such as a pesticide or termite-deterrent agent.

In another embodiment the termite barrier material comprises a solid. It 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 sujm 10676419 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, mineral slag, hard plastic, 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 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 15 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 released into the aperture expands to a sufficient extent so as to fill any gap between the aperture 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 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).

sujm 10676419 One product suitable for usc 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 to 7mm, more preferably in the range of from 1.13 to 5mm, 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 termite barrier material in the form of a particulate material or an aggregate layer may be lightly compacted in the aperture. In cases where the sacrifice of the element or part thereof creates a shortfall in the amount of termite barrier material in the aperture, the aperture may be topped up with termite barrier material.

A building aperture according to the present invention may be provided with replenishment means whereby to replenish the gap or void between the slab penetration and an edge of the aperture 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.

In one preferred embodiment, a termite barrier material in accordance with the invention substantially fills the building aperture and is compacted to ensure complete oeoo ***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 released into the building aperture to a depth which is substantially impenetrable to termites. Most preferably this depth is in the range of from about 30mm to about Activation of the termite barrier material typically comprises release of the termite barrier material into the aperture whereby to form a termite barrier for the aperture.

An at least partly sacrificial element according to the invention may take any suitable form. The arrangement is preferably such that the element is formed from a material which is at least partly destroyed, dissolved or otherwise sacrificed to permit release of the termite barrier material into the building aperture. Suitable materials for use sujm 10676419 as an at least partly sacrificial element in accordance with the present invention include oil or paraffin derivatives or other materials capable of holding a termite barrier material.

Other materials are envisaged as being suitable for use as an element in accordance with the present invention.

The element material may in one embodiment hold the termite barrier material in a matrix. The termite barrier material may in this embodiment be dispersed in or through the matrix. The termite barrier material may in another embodiment be bonded by or to the element material. In this embodiment the element material comprises an adhesive. In another embodiment the element may comprise an envelope or other membrane in which the termite barrier material is held. The envelope may fully enclose the termite barrier material. The envelope or membrane is preferably thin so that there is not a significant gap between the slab and the termite barrier material. Other element constructions and arrangements are envisaged within the scope of the invention.

In a presently preferred embodiment a significant proportion of the element is S 15 sacrificed following its placement across a building aperture to facilitate release of the o termite barrier material into the aperture.

The means by which the element is at least partly sacrificed may take any suitable form. It may comprise the application of heat. It may comprise the application of steam or other heated vapours. It may comprise the application of a solvent or a mixture of solvents selected to dissolve the element material. The solvent may be organic. It may comprise a combination of heat and one or more solvents. Other means by which the element is at least partly sacrificed are envisaged within the scope of the invention.

The element arrangement is typically such that the matrix or envelope can form or otherwise be worked following formation into a shape to suit specific dimensional requirements of the building aperture. The element holding the termite barrier material may accordingly take on or be cast or moulded into the required shape such as a formwork collar, or it may be cut into the required shape following formation such as by an band saw or similar cutting device located at or carried to the building site. Suitable shapes include polygons and circular shapes such as discs or cylinders.

The element may in one embodiment comprise formwork for the building aperture.

In this embodiment the formwork in the form of a sacrificial collar is placed around the slab penetration, and after the slab has been laid and set to a sufficient extent that sujm 10676419 substantial movement will generally not result, the collar is at least partly removed by sacrifice of the formwork material to release the termite barrier material and the gap or void filled with a termite barrier material.

The collar may be elongated. The 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 one particularly preferred arrangement an element comprising formwork in the form of a sacrificial collar holding particles of graded aggregate of a suitable stone type is 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, the collar is sacrificially removed from around the penetration and the termite barrier material such as graded stone aggregate is released into the building aperture whereby to form a termite barrier.

•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 an element according to the present invention holding a termite barrier material, the •element on at least partial sacrifice releasing the termite barrier material into the building aperture to provide a termite barrier for the building.

Preferably the element is capable of being positioned in or about a building aperture formed adjacent a slab penetration, adjoining slab or adjoining masonry. The element preferably fully surrounds the perimeter of the building aperture, whereby the element is capable of holding the termite barrier material in proximity to the perimeter surface of the adjoining slab or slab penetration for subsequent release into the building aperture. This i •construction may be adapted to maintain contact between the termite barrier material and 25 the perimeter surface of the slab penetration, an adjoining slab or adjoining masonry when the element has been sacrificed, preventing possible pathways for termites from forming in the building aperture between the slab and the slab penetration or between the slab and an adjacent slab or masonry.

The element may be suitably positioned across, in or adjacent the proposed building aperture prior to laying the building slab or an adjoining slab or masonry.

sujm 10676419 The element is preferably positioncd between the substratum and the slab prior to laying the slab whereby the element becomes embedded in the slab to some degree when the slab is laid and thereby positioned to facilitate release of a termite barrier material held therein into the building aperture.

The element may be apertured to facilitate positioning of the element adjacent and preferably substantially surrounding a slab penetration. The internal diameter or width of the element aperture is preferably slightly larger than the perimeter dimension of the slab penetration whereby to enable the element to be positioned around the perimeter of the slab penetration. The shape of the element is suitably adapted to conform with the crosssectional 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 element aperture and the slab penetration, whereby there is effectively no clearance between the termite barrier material released into the building aperture and the slab penetration so that there is no easy pathway for termites.

s. 15 In one embodiment the element is capable of engaging with the slab penetration.

The at least partly sacrificial element may comprise a collar, trough, container, cup, cage or other shape capable of holding the termite barrier material for release into the building aperture. Where the element 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 element comprises a substantially U-shaped trough holding a termite barrier material 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. When the abutting slabs are cast the lugs of the trough become at least partially embedded in adjacent slabs whereby to secure the element across the building aperture between abutting slabs and thereby on release of the termite barrier material from the element to form a termite barrier for the construction joint. The sujm 10676419 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.

In one typical embodiment of the invention, the element is generally in the shape of the building aperture formed adjacent the slab penetration across which the element 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 element may 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.

In another typical embodiment of the invention, the element is generally in the shape of the building aperture formed adjacent to the slab edge or masonry against which the element is to be positioned. For example where the building aperture is substantially rectangular the gap or void formed around the slab penetration may be elongated whereby the element may comprise a substantially rectangular sleeve capable of being positioned in 15 the gap or void and extending along at least part of the building aperture.

An element according to the present invention may be capable of being at least partly anchored to the building slab. The anchoring may be such as 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 20 one embodiment, the anchoring arrangement comprises one or more ridges, wings or lugs.

An element according to the invention may be formed from one or more components. If the element is formed from one component, the holder is preferably apertured to a dimension larger than the width of a slab penetration. This arrangement Senables the element to be slipped over a slab penetration and positioned relative to the 25 penetration whereby to release the termite barrier material into the gap or void between slab and penetration adjacent the penetration. The element aperture is preferably located on a central axis of the element.

An element according to the invention may be formed with 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 element in the region of the base of the sujm 10676419 element. In another embodiment the base may comprise a plurality of discrete feet extending outwardly from the element in the region of the base of the element.

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 s substratum on which the slab is to be laid, excavating for a slab penetration, fixing the desired position of the slab penetration with respect to the slab to be laid, positioning formwork comprising an at least partly sacrificial element holding a termite barrier material around at least part of the perimeter of the slab penetration, laying the slab and curing it for a sufficient time whereby to form a building aperture, and sacrificing at least part of the element to release the termite barrier material into the aperture, whereby to form a termite barrier.

In another 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, preparing for a building aperture, positioning 15 formwork comprising an at least partly sacrificial element holding a termite barrier 4.

°°material along the proposed building aperture, laying the slab and curing it for a sufficient time whereby to form a building aperture, and sacrificing at least part of the element to release the termite barrier material into the aperture, whereby to form a termite barrier.

An at least partly sacrificial element according to the present invention may *4*4 comprise a holder as described in our Australian Patent Application No 53596/99, the contents of which are incorporated herein by this cross-reference, or a holder as described in Australian Patent No 698397 (28459/95), the contents of which are also incorporated herein by this cross-reference. In these embodiments the holders as described are modified *so as to be at least partly sacrificial. A termite barrier material according to the present invention may be released directly into a building aperture formed with a holder in place to retain the termite barrier material following at least partial sacrifice of the element.

Description of the drawings The invention will now be further explained and illustrated by reference to the accompanying drawings in which: Figure 1 is a cross-sectional elevation of a typical building construction arrangement according to one embodiment of the present invention; sujm 10676419 Figure 2 is a cross-sectional elevation of a typical element according to one embodiment of the present invention; and Figures 3, 4 and 5 are cross-sectional elevations exemplifying various building aperture shapes and arrangements in accordance with the invention.

Turning to the drawings, Figure 1 shows part of a formed building in cross-section comprising 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 7 is erected on upper surface 4 of slab 1. The slab 1 is laid directly over the prepared substratum 9 such that the lower surface 8 of slab 1 abuts the upper surface of the substratum 9. A vapour membrane (not shown) may be interposed between the prepared substratum 9 and the slab 1 prior to laying of the slab 1.

i' "•Slab penetrations 10 and 11 are provided through slab 1 via building apertures in 15 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 (not shown) as described herein positioned to define a building aperture adjacent the slab penetration.

A slab penetration in the form of an electrical conduit 20 includes a layer of particulate termite barrier material released into the cavity between inner wall 7 and outer brick wall 6. In the embodiment shown, conduit 20 includes an element 21 according to the invention.

"i ~Element 21, which in the embodiment shown comprises a formwork section fabricated from an oil or paraffin derivative or other material capable of holding particles of termite barrier material, is positioned along a building aperture in the form of a wall cavity 40 generally in the horizontal direction of the wall cavity Formwork collar 14 is removed after concrete slab 1 is cured such as by the application of heat and/or solvent.

The embodiment of Figure 3 shows a building aperture 23 between an existing slab 26 and a new slab 25. Element 14 is in the embodiment shown in the form of a binder material holding a matrix of termite barrier material in the aperture, the barrier material sujm 10676419 being activated by release into the aperture 23 when the binder is dissolved such as by heat or solvent. Wings 28 are provided to secure a base retainer to the slabs 25, 26 to limit the degree to which the termite barrier material is affected by movement of the slabs 25, 26 such as by settling. A removable solid material 27 in the form of a block of wood, plastic, metal or other suitable resilient material can be inserted into the building aperture 23 to reduce the volume of the aperture and also to provide a stable upper surface which can be screeded off against when the slab 25 is poured.

Figure 4 shows a different shaped building aperture 23 having an element 14 holding a termite barrier material between two new beam section slabs 25, 26, the slabs l0 having reinforcing ties or dowells 29 to tie the two slabs 25, 26 together to limit the degree to which the slabs can move backwards and forwards, or up and down relative to one another.

""Figure 5 shows another different type of building aperture 23 between a building slab 25 and masonry 30, the termite barrier material 18 following release substantially filling aperture 23. Fill 33, foundation 34, footing 31 and mortar 32 are provided in accordance with that generally known in the art.

In use, with reference to Figure 1 substratum 9 is prepared on which a concrete slab I1 is to be laid, including excavation for one or more slab penetrations. An element 14 according to the invention in the form of a formwork collar holding particles of termite °20 barrier material 18 in a matrix such as, for example, a graded stone aggregate, is placed over the slab penetration such as pipework to define a building aperture around the penetration. The slab 1 is laid and cured, and the formwork is removed, such as by

*CC.

dissolving with an organic solvent. The termite barrier material is as a consequence released into the aperture so formed and substantially fills the aperture. The barrier material preferably fills the aperture to a minimum depth of approximately 75mm. The termite barrier material may then be compacted.

In an alternative arrangement of the embodiment of Figure 1, in use substratum 9 is prepared on which a concrete slab 1 is to be laid, including preparation for one or more building apertures. An element according to the invention in the form of formwork holding particles of termite barrier material in a matrix such as, for example, a graded stone aggregate, is placed along the building aperture. The slab 1 is laid and cured, and the formwork is removed, such as by dissolving with an organic solvent and/or by heating.

sujm 10676419 14 The termite barrier material is as a consequence released into the aperture so formed and substantially fills the aperture. The barrier material preferably fills the aperture to a depth in the range of from about 30m to 75mm. The termite barrier material may then be compacted.

The element provided by the present invention has the advantage that no separate formwork is required to form a building aperture. In a preferred embodiment the termite barrier material in effect constitutes the formwork. A termite barrier is accordingly capable of being readily installed to prevent termite access and maintain the integrity of the termite barrier material with respect to a building aperture.

A building may thus be protected from termite attack by the provision in any building aperture of a termite barrier material held for release by an element according to the present invention.

The word 'comprising' and forms of the word 'comprising' as used in this °description and in the claims does not limit the invention claimed to exclude any variants 15 or additions.

Modifications and improvements to the invention will be readily apparent to those **.skilled in the art. Such modifications and improvements are intended to be within the scope of this invention.

sujm 10676419

Claims (24)

1. A termite barrier for a building aperture, the barrier comprising a termite barrier material held by an at least partly sacrificial element wherein the sacrificial element binds together at least a part of the termite barrier material, the arrangement being such that on sacrifice of at least part of the element the termite barrier material is activated to form a termite barrier for the aperture.

2. The termite barrier according to claim 1, wherein activation of the termite barrier material comprises release of the termite barrier material into the building aperture to form a termite barrier for the building aperture.

3. The termite barrier according to claim 1 or 2, wherein said termite barrier material is provided in an amount sufficient to permit its release into the building aperture to a depth which is substantially impenetrable to termites.

4. The termite barrier according to claim 2 or 3, wherein on release of the termite barrier material into the building aperture the termite barrier material substantially 15 fills the building aperture. .o

5. The termite barrier according to any one of the preceding claims, wherein the at least partly sacrificial element holds the termite barrier material whereby to form a matrix with the termite barrier material.

6. The termite barrier according to any one of claims 1 to 4, wherein the at least partly sacrificial element further comprises an envelope or membrane in which the termite barrier material is held.

7. The termite barrier according to any one of claims 1 to 5, wherein the termite barrier material is in the form of particles held in a cluster by the at least partly sacrificial element. 25 8. The termite barrier according to claim 7, wherein the particles comprise a graded aggregate.

9. The termite barrier according to claim 8, wherein the aggregate is of a suitable stone type. The termite barrier according to any one of the preceding claims, wherein the sacrificial element further comprises a formwork collar. arsm M0111281568v2 304624948 16

11. A method for forming a termite barrier in a building aperture, the method comprising the steps of: placing an at least partly sacrificial element across a building aperture, the sacrificial element holding a termite barrier material wherein the sacrificial element binds together at least a part of the termite barrier material; and activating the termite barrier material by sacrifice of at least part of the sacrificial element, whereby to form a termite barrier in the building aperture.

12. The method according to claim 11, wherein the building aperture is formed around at least part of the perimeter of a slab penetration.

13. The method according to claim 12, wherein the building aperture forms an annulus around the slab penetration whereby the building aperture extends fully around the perimeter of the slab penetration.

14. The method according to any one of claims 1 1 to 13, wherein activation of the termite barrier material comprises release of the termite barrier material into the building aperture to form a termite barrier for the building aperture. The method according to claim 14, wherein on release of the termite barrier material into the building aperture the termite barrier material substantially fills the building aperture.

16. The method according to any.one of claims 11 to 15, wherein the at least partly sacrificial element holds the termite barrier material whereby to form a matrix with o 00 the termite barrier material. °oe•

17. The method according to any one of claims 11 to 15, wherein the at least partly 0 *o "000 sacrificial element further comprises an envelope or membrane in which the termite 25 barrier material is held. 0 •i 18. The method according to any one of claims 11 to 17, wherein the termite barrier material is in the form of particles held in a cluster by the at least partly sacrificial element.

19. The method according to claim 18, wherein the particles comprise a graded aggregate. arsm M01 11281568v2 304624948 17 The method according to claim 19, wherein the aggregate is of a suitable stone type.

21. The method according to any one claims 11 to 20, wherein the sacrificial element further comprises a formwork collar.

22. The method according to any one of claims 11 to 21, wherein part of the sacrificial element is capable of being anchored to a building slab in which the building aperture is formed.

23. The termite barrier formed according to the method of any one of claims 11 to 22.

24. A method for forming a building slab having a termite barrier in a building aperture formed therein, the method comprising the steps of preparing a substratum on which a slab is to be laid, excavating for a slab penetration, placing a formwork around the slab penetration to define a building aperture around the penetration, the formwork comprising an at least partly sacrificial element with which a termite barrier material is held wherein the sacrificial element binds together at least a part of the termite barrier material, pouring concrete for forming the slab, and after a suitable period sacrificing at least part of the formwork whereupon the termite barrier material is activated by release into the aperture, whereby to form a building slab having a termite barrier in the aperture. A building slab formed according to the method of claim 24.

26. A method for forming a building slab having a termite barrier for a joint to be formed therein or about a perimeter thereof with an adjacent slab or masonry, the joint forming a building aperture, the method including the steps of preparing a substratum on which a slab is to be laid, placing a formwork along the proposed ~joint for forming the building aperture, the formwork comprising an at least partly 25 sacrificial element with which a termite barrier material is held wherein the sacrificial element binds together at least a part of the termite barrier material, pouring concrete for forming the slab, and after a suitable period sacrificing at least part of the formwork whereupon the termite barrier material is released into the aperture, whereby to form a building slab having a termite barrier in the aperture.

27. A building slab formed according to the method of claim 26. arsm MOI 11281568v2 304624948 18

28. A termite barrier for a building aperture according to claim 1, substantially as hereinbefore described and with reference to any one of the accompanying drawings.

29. A method for forming a termite barrier in a building aperture according to claim 11, substantially as hereinbefore described and with reference to any one of the accompanying drawings. A method for forming a building slab having a termite barrier in a building aperture formed therein according to claim 24, substantially as hereinbefore described and with reference to any one of the accompanying drawings.

31. A method for forming a building slab having a termite barrier for a joint formed therein or about a perimeter thereof according to claim 26, the joint forming a building aperture, substantially as hereinbefore described and with reference to any one of the accompanying drawings. Granitgard Pty Ltd 15 July 2004 S* *oogo *o arsm M 111281568v2 304624948