AU742338B2 - Termite barrier insert - Google Patents

Description

1

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name of Applicant: Actual Inventor: Address for Service: Invention Title: TERMITE TITE PTY LTD TERRY JOHN TRAPNELL CULLEN CO., Patent Trade Mark Attorneys, 240 Queen Street, Brisbane, Qld. 4000, Australia.

TERMITE BARRIER INSERT Details of Associated Provisional Application: No. PP4016 filed 11 June 1998 The following statement is a full description of this invention, including the best method of performing it known to us: BACKGROUND OF THE INVENTION This invention relates to the protection of buildings from subterranean termites. The invention is particularly concerned with a termite barrier keeper for fixing to the vertical face of a concrete slab of a slabon-ground masonry veneer building, which keeper enables a flat sheet termite barrier, extending from the masonry veneer, to be physically joined to the concrete slab.

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 the use of stainless steel mesh, graded stone or 25 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 my have no effect whatsoever after as little as twelve months from application.

S Graded stone barriers must satisfy a large number of criteria to be effective. The stone must be of crushed igneous or metamorphic origin, be from a sound 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 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 25 parging 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 S-integrity of the seal is therefore frequently broken and regions for termite entry are provided.

DESCRIPTION OF THE PRIOR ART 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 regions where the three planes of the sheet meet which function to assist the barrier to resist sheer fracture when the barrier is set in the concrete slab and masonry wall.

Another method of addressing this problem is the subject of my co-pending patent application no.

87117/98 where I describe 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 building, which receptor is configured so as to grip a continuous sheet of termite barrier when inserted edgewise therein and to prevent the passage of termites past the receptor.

The former of the aforementioned termite barriers is such that it needs to be arranged and positioned before the concrete slab is poured as it extends into, and is retained by, the concrete slab.

Such a requirement also holds for the termite barrier receptor described in the later of my aforementioned copending patent applications. However, it is sometimes oooe not expedient to set the termite barrier or receptor in .the slab, or the initial placement of any such barrier prior to pouring the slab may have been simply 25 overlooked.

6 0 OBJECT OF THE INVENTION 004.

It is therefore an object of the invention to S-provide an alternative form of termite barrier formation in slab-on-ground masonry veneer buildings which can be placed in situ after the concrete slab has been poured, O but before the masonry cladding has been commenced.

S"SUMMARY OF THE INVENTION 35 According to the present invention there is provided a termite barrier keeper comprising a continuous length of termite resistant material having a planar portion for fixing to the vertical face of a concrete slab, and a pair of closely arranged resiliently deformable gripping elements extending substantially perpendicular to the planar portion which are designed to grip a sheet of termite barrier when inserted edgewise therein to thereby prevent the passage of termites past the keeper and the sheeting.

DETAILED DESCRIPTION OF THE INVENTION The keeper can be fixed to the concrete slab using conventional concrete fixing pins, such as nails and rivets, by driving the pins through the planar portion region of the keeper. In the case where the fixing pins are close to the slab surface, pre-drilled holes angled downwardly will need to be made in the slab to prevent the slab edge breaking away.

An approved type of adhesive or filler material can be applied to the rear face of the planar portion and/or to the top vertical edge of the concrete slab, prior to the keeper being fixed in position. The purpose of the adhesive or filler material is to ensure that a termite-tight seal is formed between the concrete slab and the keeper. Preferably, however, an inwardly S. projecting flange is formed along the upper in situ edge 25 of the keeper's planar portion so that either a bead of the adhesive or a bead of the filler material, such as silicone or the like, can be appropriately accommodated and retained to ensure the integrity of the insert against the passage of termites between the slab and the 30 insert. This bead can suitably be added after the keeper 0* has been fixed in situ.

The design of the keeper is suitably such that .0it can be readily used for concrete slabs which have rebates of either less than or greater than 35 mm. To this end, the preferred configuration is one where the pair of gripping elements extend outwardly from a location on the keeper which is close to a longitudinal edge of the planar portion. Such a configuration enables the keeper to be orientated with the pair of gripping elements either close to the concrete slab surface when the rebate is less than 35 mm or by rotation through 1800, to be spaced from the concrete slab surface when the rebate is greater than 35 mm. This design will also incorporate a flange of the aforementioned type on both longitudinal edges of the planar portion of the keeper.

The pair of resiliently deformable gripping elements have an inbuilt resiliency such that they can be sprung apart to enable a termite barrier having a sheetlike configuration to be inserted therein, and will tightly close over the termite barrier once in place to form a fully termite-tight connection. Further integrity to the joint can be achieved by applying an adhesive or filler material to the joint region.

The gripping elements will preferably be of 20 such a width as to span all, or at least the majority of oooo the cavity between the concrete slab and the masonry cladding. Suitably, each gripping element is slightly curved outwardly between its longitudinal edge •i .extremities so that an essentially elliptical-shaped 25 cavity is formed between the pair of elements. The extremities of the gripping elements are preferably splayed outwardly to form lips which facilitate the insertion of a termite barrier between the gripping elements.

The termite barrier keeper can be fabricated from any material which is termite resistant and is not oeooo affected to any detrimental degree by the salts in the concrete slab and by air and water. The preferred materials are extrudable plastics materials such as polyvinylchloride, which are also cost effective.

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

The keeper will suitably be provided in standard lengths, for instance 2.4 and 3.6m lengths, and can be butt-joined to a similar insert by a connector element which is shaped similarly to the portion of the keeper which extends between the perimeter wall and the concrete slab. An adhesive will usually be used at the point of joining to provide additional integrity to the system, that is, to ensure that termites do not pass thereby.

In use, the termite barrier keeper is fitted to the vertical face of the upper perimeter of a concrete slab using fixing pins and adhesive/filler material to ensure that termites cannot pass between the keeper and the slab; the keeper having initially been orientated as required to accord with the depth of the slab rebate as described previously.

Masonry cladding is then laid next to the concrete slab to a height which corresponds with the 25 height of the termite barrier keeper. A termite barrier in strip form is placed over the upper course of masonry and is inserted edgewise between the pair of resiliently deformable gripping elements of the keeper. The termite barrier is adhered to the keeper to ensure a termite- 30 tight joint.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a front perspective view of a .*{termite barrier keeper according to the present invention, Figure 2 is a cross-sectional view of the termite barrier keeper of Figure 1 in situ in one 8 orientation, and Figure 3 is a cross-sectional view of the termite barrier keeper of Figure 1 in situ in another orientation.

DESCRIPTION OF PREFERRED EMBODIMENT A preferred embodiment of the invention will now be described with reference to the drawings in which like reference numerals refer to like parts.

Referring firstly to Figure i, the termite barrier keeper 10 comprises a 1.2 mm thick profiled length of extruded polyvinylchloride plastics material having a planar portion 11 and a pair of resiliently deformable gripping elements 12, 13, projecting perpendicularly thereto.

Each of the gripping elements 12, 13 is curved outwardly between its ends so that the pair of elements S. form an elliptical cavity 14 between them. The gripping elements have respective outwardly splayed lips 15, 16 at their outer extremities to facilitate the insertion of a eeoc termite barrier.

Strip flanges 17, 18 are formed along the opposing longitudinal edges of the planar portion 11.

oooo These flanges are inclined inwardly from the plane of the strip at obtuse angles.

Referring to Figure 2, the keeper 10 is shown in situ in a building construction comprising a concrete •slab 21, foundations 23 and a brick veneer perimeter wall 24. This construction has a minimum 35 mm rebate, that is, the distance between the top of the concrete slab 21 and the top of the first row of bricks in the brick wall 24 is at least 35 mm. In such a construction the keeper is inverted from the orientation shown in Figure i.

The keeper 10 is fitted using tacks 20 which are inserted through the planar portion 11 into the concrete slab 21 using a hammer or other impacting tool.

The upper longitudinal edge of the keeper is arranged to be substantially parallel with the top surface of the concrete slab 21.

In order to ensure the integrity of the keeper 10 against the passage of termites between the keeper and the concrete slab 21, a bead of adhesive filler 22 is placed behind the flange 17 along its full length.

The gripping elements 12, 13 extend right across the cavity 25 to the inner face of the brick veneer wall 24 at the mortar joint 26. The mortar joint incorporates a termite barrier 27 in the form of a longitudinally extending strip of termite resistant material which overlaps the inner face of the brick veneer wall and extends between the gripping elements 12, 13.

o.o* In order to ensure that the junction between .the termite barrier 27 and the gripping elements 12, 13, 25 at the point where they meet with the brick veneer wall 24, is termite tight, a bead 28 of adhesive filler is run along the intersection.

Figure 3 illustrates a similar arrangement to S 30 Figure 2 but wherein the concrete slab has a rebate of less than 35 mm. In this situation, the termite barrier keeper 10 is orientated with the planar portion 11 extending below the gripping elements 12, 13, that is, it is rotated 1800 with respect to the orientation illustrated in Figure 2.

Also, because the fixing tack 30 is close to the surface of the concrete slab 21, it is inserted at an inclined angle in a preformed hole so that the corner edge of the slab does not break away.

All other constructional details of the Figure 3 arrangement are substantially as described in relation to Figure 2.

The termite barrier as described above is very effective in preventing termites from entering a building at the perimeter thereof, is very cost effective to produce, and is easy to install.

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

o, *o

Claims (12)

1. A termite barrier keeper comprising a continuous length of termite resistant material having a planar portion for fixing to the vertical face of a concrete slab, and a pair of closely arranged resiliently deformable gripping elements extending substantially perpendicular to the planar portion which are designed to grip termite barrier sheeting when inserted edgewise therein so as to prevent the passage of termites past the keeper and the sheeting.

2. A termite barrier keeper as claimed in claim 1, wherein the planar portion of the keeper is in the form of a longitudinally extending strip which is substantially flat.

3. A termite barrier keeper as claimed in claim 1 or claim 2, wherein the gripping elements extend outwardly from a location on the keeper which is close to a longitudinal edge of the planar portion of the keeper.

4. A termite barrier keeper as claimed in any one of claims 1 to 3, wherein the gripping elements comprise ribbons of material which curve towards each other along their longitudinal edges.

5. A termite barrier keeper as claimed in claim 4, wherein the longitudinal edge of the gripping elements 25 which are remote from the planar portion, include outwardly splayed lips.

6. A termite barrier keeper as claimed in claim wherein the lips comprise plain flat extensions which project angularly from the longitudinal edges. 30

7. A termite barrier keeper as claimed in any one of claims 2 to 6 when read through claim 2, wherein opposed edges of the longitudinally extending strip incorporate inwardly projecting flanges.

8. A termite barrier keeper as claimed in claim 7, wherein the flanges are in the form of longitudinally extending plain elements which project at obtuse angles with respect to the strip.

9. A termite barrier keeper as claimed in any one L 12 of the preceding claims, wherein the wall thickness of the keeper is within the range of 0.5 mm to 1.5 mm.

A termite barrier keeper as claimed in any one of the preceding claims, which is a polyvinylchloride extension.

11. A termite barrier keeper as claimed in any one of the preceding claims, which is formed in standard lengths of 2.4 and 3.6m.

12. A termite barrier keeper substantially as herein described with reference to the accompanying drawings. DATED this 11th day of June 1999 TERRY JOHN TRAPNELL By his Patent Attorneys CULLEN CO.