AU708389B2 - Method for joining ant capping - Google Patents

Description

METHOD FOR JOINING ANT CAPPING Technical Field The present invention relates to methods for joining ant capping and in particular to a method for adhesively bonding ant capping Background of the Invention Ant caps and shielding are commonly installed in buildings on substructures such as piers and walls and below the underside of bearers or floor joists so as to provide a physical barrier protecting the building from ants such as subterranean termites. Current methods of installing caps and shielding are detailed in Australian Standard AS 3660- 1993.

To ensure an integral barrier, sections of capping or shielding must be joined at their ends and at corners formed with the capping. Such joints are currently formed by one or more of the following methods: lock-seaming, welting and soldering; riveting and soldering; butt-jointing and welding; and fully soldering, welding or brazing.

"Further, the interface between holes in shielding and tie-down bolts passing therethrough are currently soldered and shielding skirts provided around service pipes and 20 similar connections are typically soldered, welded or brazed.

5 The current methods are time consuming and require expensive welding or oxyacetylene equipment for the application of heat required in the joining process. Such equipment is not typically required for other tasks carried out by bricklayers or carpenters who generally install the ant capping and shielding. Hence elimination of the requirement of heat application in the capping joining process would reduce capital equipment costs for these tradespersons.

Australian Standard AS 3660-1993 provides for the use of a variety of metallic materials including galvanized steel, zincanneal steel, copper, stainless steel and aluminium, copper and zinc alloys for the manufacture of capping and shielding.

[N:\LIBHH]00637:GJG

~I

However, of those available, only zincanneal steel and galvanised steel are commonly used as they are the only approved materials that can be readily and economically joined using the current methods. The other materials may be joined in some instances by welding or soldering, but specialised skills and equipment are required, thereby increasing the cost and requiring the ready availability of a specialist.

Object of the Invention It is the object of the present invention to overcome or substantially ameliorate at least some of the above disadvantages.

Summary of the Invention There is disclosed herein a method of forming a continuous bonded joint between S- first and second surfaces in an ant capping installation, comprising the steps of: *preparing said first and second surfaces such that they are substantially free of oils ooo 0. and other contaminants, .oo applying a termite impervious adhesive to at least one of said first and second o• surfaces, overlapping and mating said first and second surfaces to form a single lap joint of a required configuration, and 5mechanically holding said first and second surfaces together allowing said adhesive Sgto cure, wherein said first surface is a surface of a first section of ant cap of said ant capping installation and said second surface is a surface of a second section of ant cap of said ant capping installation.

Typically said adhesive is a two part epoxy.

Generally said adhesive is a room temperature cure adhesive.

Typically said adhesive will cure in wet or moist conditions.

Preferably said adhesive has a Shore A hardness of greater than 75 when cured.

Preferably said adhesive is resistant to pH levels of greater than 11.

Preferably said adhesive is resistant to pH levels of less than 4.

Preferably said adhesive will be "Antcapit Adhesive" B. Fuller).

[N:\LIBHH]00637:GJG:TCW Alternatively said adhesive will be "Master Builders Technologies Concressive 1446".

Alternatively said adhesive will be "Ciba Geigy Araldite Alternatively said adhesive will be "Fosroc Nitomortar

HB".

Alternatively said adhesive will be "Ciba Geigy Araldite K125" Alternatively said adhesive will be "Epires 8242".

Alternatively said adhesive will be "Epires 8641".

Preferably said first and second surfaces are mechanically held with a clamp.

Alternatively said surfaces are mechanically held with a spring clothes peg.

Preferably said single lap joint has an overlap length of at least 10 mm.

Brief Description of the Drawings e x Preferred forms of the present invention will now be described by way of S" ^example with reference to the accompanying drawings wherein:

F

Figure 1 is a partial plan view of an ant capping installation including a corner 15 shield ant cap section.

A [N:\LIBHH]00637:GJG:TCW Figure 2 is a partial plan view of another ant capping installation including a corner shield ant cap section.

Figure 3 is a partial plan view of an ant capping installation including a wall intersection shield ant cap section.

Figure 4 is a partial plan view of an ant capping installation including an engaged pier ant cap section.

Figure 5 is a partial front elevation view of an ant capping installation including a tie-down bolt passing through an ant cap.

Detailed Description of the Preferred Embodiments The current invention provides a method of forming a continuous bonded joint between first and second surfaces in an ant capping installation. The method according to a preferred embodiment comprises the steps of: 0 preparing the first and second surfaces so that they are substantially free of oils and other contaminants, thus providing a clean surface to promote a durable bond, applying an adhesive to at least one, and preferably both of the first and second surfaces, mating the first and second surfaces to form a required configuration of the joint, and mechanically holding the first and second surfaces together, typically by means of a '"*clamp, spring clothes peg or similar, allowing the adhesive to cure.

The adhesive will typically be a room temperature cure, two part epoxy adhesive.

The adhesive should also be impervious to termites and have a Shore A hardness of greater than 75 when cured. The adhesive should also be resistant to pH levels of greater than 11 and less than 4. The adhesive selection and joint design should also be carried out such that the joint will have a bond shear strength sufficient to withstand design loads of the given ant capping installation. Use of adhesives in place of the current methods enables a wider range of materials to be used for the ant capping, including all of those approved in Australian Standard AS 3660-1993 and detailed above.

[N:\LIBHH]00637:GJG Preferred embodiments of the method may be used for several joints in typical ant capping installations. Figure 1 depicts a portion of an ant capping installation 11 comprising a corner shield ant cap section 12 and two strip shield ant cap sections 13.

Each end joint 14 is formed as a single overlap joint, here having an overlap length of at least 10 mm. The first surface 14a of the joint 14 is a lower surface of the corner shield ant cap section 12, and is bonded to the second surface 14b which is an upper surface of the strip shield ant cap section 13. The overlap joint 14 may be readily clamped to promote adhesive cure. Similar end joints 34, 44 may be formed between wall intersection shield ant cap sections 34 and strip shield ant cap sections 13 as depicted in Figure 3, and between engaged pier ant cap sections 42, 43 as depicted in Figure 4, covering the intersection between a pier and a wall of the substructure.

For ant capping installations including corner shield ant cap sections 12, 22 as S depicted in Figures 1 and 2, the corner shield ant cap sections 12, 22 are typically either integrally pressed into shape (corner shield 12 of Figure 1) or formed from two straight is sections 22a, 22b joined with a corner joint 25 (corner shield 22 of Figure If required, the outer flanges 12a, 12b of the integrally pressed corner shield ant cap section 12 may joined 16 using the method according to the current invention to ensure an integral barrier across the ant capping. If insufficient cap material is available to make a similar joint between the inner flanges 12c, 12d, then a gusset 17 may be joined to each of the 20 inner flanges 12c, 12d, bridging the gap therebetween to ensure an integral barrier. The corner joint 25 of the corner shield ant cap 22 of Figure 2 may be formed using a single overlap joint 25 as discussed above.

For ant capping installations including a member passing through an ant cap, such as a tie-down bolt 53 used to secure a bearing member 55 to a pier 56 as depicted in Figure 5, a joint 54 may be formed according to the current invention between the surface of the hole passing through the ant cap 52 and the circumferential surface of the tie-down bolt 53 passing through the ant cap 52 so as to provide an integral barrier at the interface therebetween. Adhesive bonding may also be used to seal other such interfaces where members pass through a section of ant cap, such as where skirt shielding is used to form a 3o barrier around service pipes or similar connections.

[N:\LIBHH]00637:GJG 6 The claims defining the invention are as follows: 1. A method of forming a continuous bonded joint between first and second surfaces in an ant capping installation, comprising the steps of: preparing said first and second surfaces such that they are substantially free of oils and other contaminants, applying a termite impervious adhesive to at least one of said first and second surfaces, overlapping and mating said first and second surfaces to form a single lap joint of a required configuration, and mechanically holding said first and second surfaces together allowing said adhesive to cure, 0 wherein said first surface is a surface of a first section of ant cap of said ant capping installation and said second surface is a surface of a second section of ant cap of said ant capping installation.

15 2. The method of claim 1 wherein said adhesive is a two part epoxy adhesive.

3. The method of either of claims 1 and 2 wherein said adhesive is a room temperature cure adhesive.

4. The method of any one of claims 1 to 3 wherein said adhesive will cure in wet or moist conditions.

0 .0 20 5. The method of any one of claims 1 to 4 wherein said adhesive has a Shore A hardness of greater than 75 when cured.

6. The method of any one of claims 1 to 5 wherein said adhesive is resistant to pH levels of greater than 11.

7. The method of any one of claims 1 to 6 wherein said adhesive is resistant to pH levels of less than 4.

8. The method of any one of claims 1 to 7 wherein said adhesive is "Antcapit Adhesive" B. Fuller).

9. The method of any one of claims 1 to 7 wherein said adhesive is "Master Builders Technologies Concressive 1446".

[N:\LIBHH]00637:GJG:TCW i

Claims (6)

11. The method of any one of claims 1 to 7 wherein said adhesive is "Fosroc Nitomortar HB".

12. The method of any one of claims 1 to 7 wherein said adhesive is "Ciba Geigy Araldite K125".

13. The method of any one of claims 1 to 7 wherein said adhesive is "Epires 8242".

14. The method of any one of claims 1 to 7 wherein said adhesive is "Epires 8641". The method of any one of claims 1 to 14 wherein said first and second surfaces are mechanically held with a clamp.

16. The method of any one of claims 1 to 14 wherein said surfaces are mechanically held with a spring clothes peg.

17. The method of any one of claims 1 to 16 wherein said single lap joint has an overlap length of at least 10 mm. 15 18. A method of forming a continuous bonded joint between first and second surfaces in an ant capping installation, said method being substantially as hereinbefore described with reference to any one of Figures 1 to 4 of the accompanying drawings. *o 0 DATED this Eighth Day of June 1999 P W Saddington and Sons Pty. Ltd. Patent Attorneys for the Applicant SPRUSON FERGUSON [N:\LIBHH]00637:GJG:TCW 1 METHOD FOR JOINING ANT CAPPING Abstract In a method of forming a continuous bonded joint (14) between first and second surfaces (14a, 14b) in an ant capping installation (11) the first and second surfaces (14a, 14b) are first prepared such that they are substantially free of oils and other contaminants. A termite impervious adhesive is applied to at least one of the surfaces (14a, 14b), which are then mated to form a required configuration of the joint The surfaces (14a, 14b) are mechanically held together allowing the adhesive to cure. The first surface (14a) is a surface of a first section of ant cap (12) of the ant capping installation (11). Fig. 1 9.. et* 96 ft* 9. 9. [N:\LIBHH]00637:GJG 1