AU2012202452B2 - A method of termite proofing a penetration through a structure - Google Patents

Abstract

A METHOD OF TERMITE PROOFING A PENETRATION THROUGH A STRUCTURE A method of termite proofing a penetration (2) through a structure (1) comprises firstly coating a continuous band (4) of a flowable, settable, mixture of a cementitious composition and water along the length of an interface (5) between the penetration (2) and a face (3) of the structure (1) through which the penetration (2) protrudes. The band (4) extends from the interface (5) along a peripheral surface (7) of the penetration (2) adjacent the interface (5) and along the face (3) of the structure (1) about the interface (5). The mixture is then allowed to set. The cementitious composition is selected such that the mixture, when set, is physically impenetrable by termites such that the band (4) prevents the passage of termites through the interface (5). Fi.6 Fig. 1 ( ol Fig. 2

Description

S&F Ref: P034479 AUSTRALIA PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name and Address Termortar Pty Ltd, of Applicant: an Australian company, ACN 111 294 814, of 75 Lambton Road, Broadmeadow, New South Wales, 2292, Australia Actual Inventor(s): David Lees Saddington Address for Service: Spruson & Ferguson St Martins Tower Level 35 31 Market Street Sydney NSW 2000 (CCN 3710000177) Invention Title: A method of termite proofing a penetration through a structure Associated Provisional Application Details: [33] Country: [31] Appl'n No(s): [32] Application Date: AU 2011901586 29 Apr 2011 The following statement is a full description of this invention, including the best method of performing it known to me/us: 5845c(6237596_1) 1 A METHOD OF TERMITE PROOFING A PENETRATION THROUGH A STRUCTURE Technical Field [00011 The present invention relates to the control of termites and in particular relates to a method of termite proofing a penetration through a structure. Background of the Invention [00021 A common method of preventing termites from entering a building through a gap occurring at an interface between a concrete structure of the building, such as a concrete floor slab, and a pipe or other form of penetration penetrating through the structure, is to install a plastic collar before the concrete forming the concrete structure is poured, so that a flange of the collar extends into and is bonded to the concrete structure when the concrete structure is cured. The pipe or other form of penetration is then installed through the plastic collar with a tight fit which prevents any gap of sufficient size for termites to pass therethrough. Installing such plastic collars is a time consuming process and requires the installer to walk over reinforcing mesh that is located in situ before pouring of the concrete. This task is often difficult and dangerous to the installer. This method also requires tight co-ordination of tradespeople, with the collars needing to be installed after locating of the reinforcing mesh but prior to pouring of the concrete, often leaving the installer a very short timeframe to perform the plastic collar installation. Object of the Invention [00031 It is an object of the present invention to substantially overcome or at least ameliorate at least one of the above disadvantages. Summary of the Invention 100041 In a first aspect, the present invention provides a method of termite proofing a penetration through a structure, said method comprising: coating a continuous band of a flowable, settable, mixture of a cementitious composition and water along the length of an interface between said penetration and a face of said structure through which said penetration protrudes, said band extending from said interface along a peripheral surface of said 2 penetration adjacent said interface and along said face of said structure about said interface; and allowing said mixture to set; wherein said cementitious composition is selected such that said mixture, when set, is physically impenetrable by termites such that said band prevents the passage of termites through said interface; further wherein said cementitious composition includes cellulose ether. [0005] Typically, said penetration comprises a pipe or conduit. [0006] Typically, said structure comprises a concrete floor slab. [0007] Typically, said band extends along said face of said structure at least 50 mm beyond said interface at all locations along said interface. [0008] Typically, said band extends at least 50 mm along said peripheral surface of said penetration beyond said interface at all locations along said interface. [0009] In a preferred form, said band is applied with a brush. [0010] In one form, the method termite proofs multiple adjacent penetrations through a structure, said band extending along an interface between each said penetration and said face of said structure, along said peripheral surface of each said penetration adjacent the respective said interface and along said face of said structure about each said interface. [0011] Typically, said band, when set, has a Shore D hardness of at least 70. [0012] In a preferred form, said cementitious composition comprises: cement; sand; latex based binding agent; expanding agent; and cellulose ether. [0013] In a preferred form, said composition comprises, by weight: 20% to 25% cement; 2a 55% to 65% sand; 10% to 15% latex based binding agent; 0.002% to 0.006% expanding agent; approximately 0.003% cellulose ether. [0014] In a second aspect, the present invention provides a cementitious composition, for termite proofing a penetration through a structure, comprising: cement; 3 sand; latex based binding agent; expanding agent; and cellulose ether. Brief Description of the Drawings 100151 Preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawing wherein: [00161 Figure 1 is a schematic representation of an application of a method according to a preferred embodiment to a penetration through a concrete structure. [0017] Figure 2 is a schematic representation of an application of a method according to a preferred embodiment to multiple penetrations through a concrete structure. Detailed Description of the Preferred Embodiments 100181 Figure 1 schematically depicts a structure, in the form of a concrete floor slab 1, with a penetration, in the form of a plastic pipe 2, penetrating therethrough. The pipe 2 protrudes beyond the upper face 3 of the floor slab 1, into the interior of a building formed in part by the floor slab 1, defining an interface 5 between the upper face 3 of the concrete slab 1 and the pipe 2. The interface 5, if left untreated, generally defines a gap between the floor slab 1 and the pipe 2, through which termites may enter the building, at various locations along the interface 5. Here the interface 5 is treated by coating a continuous band 4 of a flowable, settable, mixture of a cementitious composition and water along the interface 5. The composition is typically applied by way of a paintbrush 6. 10019] The band 4 extends from the interface 5 along the peripheral surface 7 of the pipe adjacent to the interface 5. Preferably, the band 4 extends along the peripheral surface 7 of the pipe 2 a distance of at least 50 mm from the interface 5 at all positions along the interface 5. Accordingly, in the arrangement depicted, the band 4 extends at least 50 mm up the pipe 2 around the entire periphery of the pipe 2. Similarly, the band 4 extends from the interface 5 along the upper face 3 of the slab I about the interface 5. Preferably, the band extends at least 50 mm along the upper face 3 of the slab I at all locations along the interface 5. The band thus forms a readily visible inspection band and seal for the interface 5 between the pipe 2 and the floor slab 1.

4 [00201 The mixture of the cementitious composition and water forming the band 4 is then allowed to set. The cementitious composition is selected such that the mixture, when set, is physically impenetrable by termites, such that the band 4 forms a termite proof barrier preventing the passage of termites through the interface 4 between the pipe 2 and floor slab 1 into the interior of the building. [00211 One suitable general form of cementitious composition comprises a blend of: cement; sand; latex based binding agent; expanding agent; and cellulose ether. [00221 These constituents will typically be provided in granular or powder form, although the latex based binding agent may regularly be provided in a liquid suspension form. The constituents may be mixed with water to produce a thixatropic flowable slurry that will adhere to a paintbrush so as to allow simple application of the mixture to the concrete slab 1, the pipe 2, and interface 4 therebetween. The amount of water added to the composition to form the mixture may be varied as desired by the use to achieve the desired consistency of the slurry. When allowed to set, the mixture hardens to form a termite proof barrier which is chemically inert to formic acid produced by the saliva of termites. 100231 An example of a suitable breakdown of the composition by weight is: 20% to 25% cement; 55% to 65% (typically approximately 60%) sand; 10% to 15% latex based binding agent; 0.002% to 0.006% expanding agent; and 0.003% cellulose ether. 100241 A more specific example of a suitable composition comprises, by weight: 24.904% cement; 60% sand; 15% latex based binding agent; 0.006% expanding agent; and 0.003% cellulose ether.

5 100251 The mixture, when set, preferably provides a Shore D hardness of at least 70 to assist in inhibiting the passage of termites through the barrier formed by the band 4. 100261 In the context of this specification, the term "latex" has its generalised lay meaning utilised in the building trade so as to encompass latex based materials and latex derivatives. As noted above, the latex based binding agent will typically be provided in the form of a powder or liquid suspension and will not dissolve once the composition has set, even when submerged in water for extended periods. As a result, the composition may be utilised in wet areas of buildings. The latex based binding agent acts to provide a high bond strength between the composition and the concrete of the floor slab 1 and plastic of the pipe 2, as well as between the individual constituents of the composition. The latex based binding agent also provides chemical resistance from breakdown by attack from formic acid produced by termites. The latex based binding agent also provides flexibility to the composition when set, allowing the band 4 to cope with differential movement between the pipe 2 and the floor slab I after setting, thus inhibiting cracking of the band 4 which would otherwise allow for ingress of termites through the interface 5. [00271 Suitable latex based binding agents include latex acrylic polymer blends, such as BASF BARRA Emulsion 75 (also known as EMACO 157 Primer), an aqueous emulsion of styrene-butadiene copolymer latex. Other suitable commercially available latex based binding agents include Cementaid "Weldcrete", Davco "Mortarflex" and Fosroc "Nitrobond". [0028] The expanding agent, which may suitably be in the form of aluminium oxide powder or any of various other known expanding agents, reacts with water and/or other constituents of the composition to expand during the setting process, thereby compensating for shrinkage of the composition as might otherwise occur during the setting process that may result in cracking of the band. [00291 The cellulose ether, which may suitably be in the form of any of various cellulose ethers available under the trademark Methocel from The Dow Chemical Company, acts to increase the hardness of the set mixture, without needing to increase the percentage of cement in the composition that would otherwise be needed to achieve a suitable hardness. The cellulose ether also thickens the mixture, assisting in making the mixture thixatropic, so that ample amounts of the mixture of the composition and water may be readily picked up by 6 the user on the paintbrush 6 for ease and speed of application. The cellulose ether also provides high water retention to assist in providing a high ultimate set strength and hardness and has diminished cracking characteristics as compared to the cement component of the mixture. One particular preferred example of cellulose ether is Methocel 10-0307, although other forms of cellulose ether may be utilised as desired to provide specific workability properties as may be desired by individual users. 10030] The coating of a band of the mixture along the interface 5 and the external surface 7 of the pipe 2 and upper face 3 of the floor slab 1 allows for termite proofing after the concrete slab is poured, allowing visual inspection of the termite proofing after completion of the job, given that the termite proofing is not buried in the concrete and subject to damage during pouring of the concrete as is the case with the use of plastic collars as discussed above. The present method also avoids problems presently experienced when the concrete slab is poured without prior installation of the plastic collars, leaving the pipe penetration as an entry point for termites. Formation of the band using a cementitious composition also provides the band 4 with a life span similar to that of the concrete floor slab 1, thus providing excellent longevity. [00311 As depicted in Figure 2 the present method is also readily applicable to multiple adjacent penetrations, such as multiple closely grouped electrical conduits 8 that are not readily able to be protected individually with plastic collars, thus leaving the penetrations untreated. In this instance a continuous band 10 of the mixture can easily be applied to the upper face 3 of the concrete floor slab I and up the lower region of the peripheral surface 9 of each conduit 8 over an extended area encompassing multiple conduit penetrations. In such arrangements, some conduits 8 may be touching, whilst others may be spaced apart, typically by up to about 50 mm. 10032] Whilst the method of the present invention has been described with particular reference to pipe penetrations through concrete slabs, it is also envisaged that the method may be applied to any of various forms of penetration through various structures, wherever protection from termite ingress is required.

Claims (12)

1. A method of termite proofing a penetration through a structure, said method comprising: coating a continuous band of a flowable, settable, mixture of a cementitious composition and water along the length of an interface between said penetration and a face of said structure through which said penetration protrudes, said band extending from said interface along a peripheral surface of said penetration adjacent said interface and along said face of said structure about said interface; and allowing said mixture to set; wherein said cementitious composition is selected such that said mixture, when set, is physically impenetrable by termites such that said band prevents the passage of termites through said interface; further wherein said cementitious composition includes cellulose ether.

2. The method of claim 1, wherein said penetration comprises a pipe or conduit.

3. The method of either of claims 1 and 2, wherein said structure comprises a concrete floor slab.

4. The method of any one of claims 1 to 3, wherein said band extends along said face of said structure at least 50 mm beyond said interface at all locations along said interface.

5. The method of any one of claims 1 to 4, wherein said band extends at least 50 mm along said peripheral surface of said penetration beyond said interface at all locations along said interface.

6. The method of any one of claims 1 to 5, wherein said band is applied with a brush.

7. The method of any one of claims 1 to 6, wherein said method termite proofs multiple adjacent penetrations through a structure, said band extending along an interface between each said penetration and said face of said structure, along said peripheral surface of each said penetration adjacent the respective said interface and along said face of said structure about each said interface.

8. The method of any one of claims 1 to 7, wherein said band, when set, has a Shore D hardness of at least 70. 8

9. The method of any one of claims 1 to 8, wherein said cementitious composition comprises: cement; sand; latex based binding agent; expanding agent; and cellulose ether.

10. The method of claim 9, wherein said composition comprises, by weight: 20% to 25% cement; 55% to 65% sand; 10% to 15% latex based binding agent; 0.002% to 0.006% expanding agent; approximately 0.003% cellulose ether.

11. A cementitious composition, for termite proofing a penetration through a structure, comprising: cement; sand; latex based binding agent; expanding agent; and cellulose ether.

12. The composition of claim 11, wherein said composition comprises, by weight: 20% to 25% cement; 55% to 65% sand; 10% to 15% latex based binding agent; 0.002% to 0.006% expanding agent; approximately 0.003% cellulose ether. Termortar Pty Ltd Patent Attorneys for the Applicant/Nominated Person SPRUSON & FERGUSON