Physical Barriers
Physical barrier treatments are most often used for termite protection in new constructions. A physical barrier is designed to isolate the termite colony from the building under attack so that the termites’ only method of entry is over a designated perimeter inspection zone.
That’s because termites will usually avoid constructing shelter tubes up the side of walls unless provided with ample water or additional shelter – they prefer the easy way in.
In this way, physical barriers provide the least-toxic means of termite management for new buildings.
Where possible, it’s preferable to eliminate any detected colonies before installing remedial barriers.
Strip Shielding
Metal ant caps are often seen on the tops of stumps under suspended timber floors. These don’t actually prevent termite attack. However, if installed properly, the termites will have to construct an obvious mud tube over the cap to penetrate the building. These tubes are easily identified during a termite inspection which should be conducted yearly to comply with the Australian Standard. Similarly, metal sheeting is often used through brick piers and masonry walls to force termites to the outside but is not generally used in the industry any more as it has not proven overly successful over time.
Granite Aggregate
Crushed granite of a particular particle shape and size range is also used as a physical termite barrier. The termites are unable to penetrate the granite as the particles are too large and heavy for them to move. Granite is most often used with concrete slabs where it is applied around pipes and behind the lower bricks at the building perimeter; however, this product has largely become obsolete with the introduction of cheaper and more effective termite membranes.
Stainless Steel Mesh
Marine grade stainless steel mesh may also be used as a physical barrier to termites. The size of the mesh openings is small enough to prevent the termites passing through. Mesh is commonly glued to slabs and masonry and may be also be used around pipes through slabs. As is the case with granite guard, this product has mostly become obsolete due to the advancement of termite membranes which are cheaper and more effective.
Termite Membranes or Chemically Impregnated Sheets
The advancement of chemically impregnated membranes has made this method of pre-construction protection safe, affordable and very effective. The products range from sealant to dampcourse membranes and use active ingredients such as bifenthrin and deltamethrin impregnated into the fibres, sheeting, or geotextile to act as a permanent and effective barrier to termites.