AU8711798A - Termite barrier receptor - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT rr o o

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r o oo o Name of Applicant: Actual Inventor: Terry John TRAPNELL Terry John TRAPNELL Address for Service: CULLEN CO., Patent Trade Mark Attorneys, 240 Queen Street, Brisbane, Qld. 4000, Australia.

Invention Title: TERMITE BARRIER RECEPTOR Details of Associated Provisional Application: Nos. P09562 filed 1 October 1997 The following statement is a full description of this invention, including the best method of performing it known to me j 2 BACKGROUND OF THE INVENTION This invention relates to the protection of buildings from subterranean termites. The invention is particularly concerr.sd with receptor inserts for incorporating into the perimeter of concrete slabs of slab-on-ground masonry veneer buildings, which enable termite barriers, extending from the masonry veneer, to be physically fitted into the slabs.

Subterranean termites typically build nests just beneath the soil surface and forage, principally for cellulose containing material, for distances which can reach hundreds of metres from their nests. Termite damage to buildings, particularly residential buildings can be as many as one building in five in some parts of Australia, costing the community many tens of millions of dollars annually in the repair of the affected timber. As a 'result, the Australian Building Code has made it compulsory for all new buildings to incorporate suitable termite barriers. The current Building Code is laid down in Australian Standard 3660.1-1995. This standard specifies three permissible systems for protecting concrete slabs from termite penetration. The systems comprise the use of stainless steel mesh, graded stone or chemicals.

Chemical soil barriers have recently come under attack by environmentalists on the basis that their toxicities may be harmful to man. This has lead to the banning of conventional chemicals and the use of more environmental friendly materials. Unfortunately, such materials are less effective and may have no effect whatsoever after as little as twelve months from application.

Graded stone barriers must satisfy a large number of criteria to be effective. The stone must be of .S 35 crushed igneous or metamorphic origin, be from a sound Si source, have a minimum sg of 2.52, and be graded and shaped so that the termites cannot lift them or penetrate their voids. A typical product meeting these requirements IS i 1 3 is GRANITGARD® which is a granite stone supplied by CSR Readymix, a Division of CSR Limited. The problem with such products, however, is that they cannot effectively be used on sloping ground surfaces, supply in many parts of Australia is difficult, and they are relatively expensive.

Stainless steel mesh barriers are consequently now in widespread use. These barriers are, nevertheless, not without their drawbacks. Apart from their high cost which cannot be avoided, there are particular problems when it comes to their installation at the perimeter of concrete slabs having masonry veneer walls. The commonly used method comprises parging an inner edge of the mesh to .the perimeter of the slab and extending the mesh out under :the row of bricks, which is substantially level with the slab. The parging material is an adhesive which is required to be termite resistant, form a strong bond between the mesh and the concrete, and be durable over the life expectancy of the building. In practice, however, it is difficult to form a proper seal with the parging 20 material due to the relative movement between the bricks and the concrete slab due to different rates of drying, and expansion and contraction taking place. The integrity of the seal is therefore frequently broken and regions for termite entry are provided.

One method of satisfactorily addressing this problem is the subject of my co-pending patent application no. 64411/96 wherein I provide a termite barrier comprising a continuous sheet of termite resistant material having a substantially Z-shaped profile incorporating movement resisting deformations, and curved P regions where the three planes of the sheet meet which f^ function to assist the barrier to resist sheer fracture -when the barrier is in place. The barrier is set into the upper perimeter of the concrete slab so as to extend into I: 35 the masonry veneer surrounding the slab. However should T the bricklayer not properly set his brick courses to the i ~correct height, the barrier will not be in the proper position to extend across the upper brick course and the r i i 4 integrity of the system might be compromised.

OBJECT OF THE INVENTION It is therefore an object of the invention to provide an effective means of enabling a termite barrier to be placed at the perimeter region of a concrete slab of a slab-on-ground masonry veneer building, so that the aforementioned problems are either completely obviated or significantly reduced.

SUMMARY OF THE INVENTION S: According to the present invention there is provided a termite barrier receptor comprising a I' continuous length of termite resistant material designed for retention within the perimeter of a concrete slab of a slab-on-ground masonry veneer building, which receptor is configured so as to retain a continuous sheet of termite barrier when inserted edgewise therein and to prevent the passage of termites from one side of the termite barrier 20 to the other side at the region of insertion.

DETAILED DESCRIPTION OF THE INVENTION The provision of such a receptor enables a termite barrier to be put in place after the concrete slab has been formed and during the construction of the masonry veneer cladding.

Preferably, the receptor is configured so as to include a longitudinal cavity which extends a sufficient depth into the concrete slab so as accommodate variations in the degree of penetration of the termite barrier brought about by variations in the distance between the concrete slab and the masonry cladding, as will typically occur during the construction of buildings. k The termite barrier can be retained by a gripping or jaw arrangement formed by the receptor. The Sjaw arrangement is suitably located in an exterior facing Sregion of the receptor. A preferred jaw arrangement consists of two longitudinally extending opposed

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contiguous sections formed at the entry to a cavity defining portion which extends into the concrete slab.

Such contiguous sections can be temporarily held apart during the laying of the concrete slab by means of a removable spacer element such as a strip of waxed cardboard or the like extending between them.

The receptor can include longitudinally extending flanges which project on each side of the gripping arrangement and which lie in the plane of the concrete slab perimeter. Such flanges reinforce the gripping action of the receptor as well as provide a visual aid to the location thereof and assist in the placement of the termite barrier therein.

Preferably, winged elements are formed on the 15 longitudinal edge of each flange and extend into the concrete slab to provide additional keying of the receptor to the concrete slab. Further keying elements can extend -from the receptor insert body and are ideally located at AI the position where the receptor extends to its maximum 20 depth in the concrete slab. These further keying elements can be of a smaller size than the winged elements.

Typical of such keying elements are longitudinal angular ribs.

S" The receptor can be fabricated from any material which is termite resistant and is not affected to any significant detrimental degree by the salts in the concrete slab or by air or water. The preferred materials are those which can be continuously extruded, for instance plastics materials such as polyvinylchloride and polyethylene.

The wall thickness of the receptor will generally lie within the range of 0.5 to 1.5mm, preferably about 1.2mm.

The receptor will suitably be provided in standard lengths, for instance 3.6m lengths, and can be butt-joined to a similar receptor by a connector element k; which is shaped similarly to the portion of the receptor which extends into the concrete slab. An adhesive will 6 usually be used at the point of connection to provide additional integrity to the system, that is, to ensure that there are no passageways through which termites could pass.

s In use, the termite barrier receptor is incorporated into the perimeter of a concrete slab during the pouring of the slab, suitably within a few centimetres of the surface of the slab. If the concrete slab is rebated, the receptor will be located in the rebate base.

The receptor is arranged to be substantially horizontal and will typically incorporate a removable spacer element, as mentioned above, at least until the concrete has set.

The masonry cladding along the slab perimeter is subsequently built to a height which is slightly below the 15 height of the receptor, and is spaced apart from the concrete slab, in accordance with normal building practice. A termite barrier is placed over the upper course of masonry cladding at this point and is inserted edgewise into the receptor, bridging the cavity between 20 the cladding and the slab. The masonry cladding is then Scontinued on up in the normal manner.

4444In this way, the building is effectively protected from subterranean termites in a simple and cost- 4 effective manner and the integrity of the termite barrier is no predicated upon the need for precise construction of the veneer cladding. That is, the cladding can vary from }the preferred height and spacing from the concrete slab without affecting the ability to place the termite barrier between the cladding and the concrete slab and still achieve the same protection from termites BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a rear perspective view of a termite barrier receptor according to the present invention, and Figure 2 is a cross-sectional view of the termite barrier receptor of Figure 1 in situ in a concrete ;i slab.

I DESCRIPTION OF PREFERRED EMBODIMENT A preferred embodiment of the invention will now be described with reference to the drawings. In both of the drawings, like reference numerals refer to like parts.

Referring to both drawings, the termite barrier receptor comprises a 1.2mm thick profiled continuous length of polyvinylchloride material having a pair of opposed longitudinal curved walls 11, 12 defining an internal cavity 13 and having gripping means 14. The gripping means 14 consists of a pair of opposed longitudinally extending jaws 15, 16 which are separated from one another I by an amount equal to the thickness of a sheet termite barrier 9 placed therein as shown in Figure 2.

Plane faced flanges 17, 18 extend outwardly from the jaws 15, 16 and lie in the outer vertical plane 20 of the concrete slab 19. Winged angular elements 21, 22 extend from the end of each flange 17, 18 to provide additional keying of the receptor in the concrete slab 19.

S 20 Further keying elements 23, 24 are formed adjacent the terminal end of the walls I, 12 of the receptor. The keying elements ensure that the receptor is properly locked in situ.

As shown in Figure 2, the receptor 10 is 25 embedded in the concrete slab 19 approximately 2cm from the slab surface 25 and in the perimeter region of the slab adjacent to where a brick cladding 26 is (subsequently) erected. The termite barrier 9 is laid over the brick course and projects at a slightly upwardly inclined angle towards the concrete slab 19 before projecting horizontally into the receptor.

Such an arrangement provides a secure and effective barrier to the passage of termites from one side of the termite barrier 9 to the other side.

Whilst the above has been given by way of illustrative example of the invention, many modifications 77 and variation may be made thereto by persons skilled in 8 the art without departing from the broad scope and anmbit of the invention as herein set forth.

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Claims (6)

1. A termite barrier receptor comprising a continuous length of termite resistant material designed for retention within the perimeter of a concrete slab of a slab-on-ground masonry veneer building, which receptor is configured so as to retain a continuous sheet of termite barrier when inserted edgewise therein and to prevent the passage of termites from one side of the termite barrier to the other side at the region of insertion.

2. A termite barrier receptor as claimed in claim i1, wherein the receptor includes a pair of opposed longitudinally extending curved walls defining a longitudinal cavity therebetween, which walls can extend into the concrete slab to such a distance as to accommodate variations in the degree of penetration of the termite barrier which can be inserted between them.

3. A termite barrier receptor as claimed in claim 20 2, wherein the receptor includes a gripping arrangement to retain the termite barrier in situ, which gripping arrangement consists of two longitudinally extending opposed contiguous sections formed at the entry to the cavity defining portion.

4. A termite barrier receptor as claimed in claim 3, wherein longitudinally extending flanges project on each side of the gripping arrangement and are adapted to lie in the plane of the concrete slab perimeter. A termite barrier receptor as claimed in claim 4, wherein winged elements are formed on the longitudinal edge of each flange and are adapted to extend into the concrete slab to provide a means to assist the keying of the receptor to the concrete slab. A termite barrier receptor as claimed in any one ,t v.~ of claims 2-5, wherein longitudinally extending elliptical cross-sectional the cavity walls has profile. defined by the a substantially substantially as the accompanying

7. A termite barrier receptor herein described with reference to drawings.

8. A concrete slab whenever formed with a termite 10 receptor as defined in any one of the preceding claims. DATED this 29T DAY OF September 1998 TERRY JOHN TRAPNELL By his Patent Attorneys 15 CULLEN CO. a I: