Dennis Ring, Henderson, Gregg, Morgan, Alan L. | 6/12/2009 9:32:35 PM
Termimesh (TERMI-MESH Australia Pty. Ltd; Termimesh LLC, Austin, Texas) is a physical barrier designed to exclude termites from structures. It is made of high-grade corrosion-resistant stainless steel wire that is finely woven into a flexible mesh sheet. The rectangular apertures between the woven wires measure 0.45 by 0.66 mm and are small enough to prevent termites from passing through them. Termites cannot chew through the wire (0.18 mm diameter). The product is installed by trained professionals. The professionals are tested and accredited on proper installation techniques. Independent inspectors conduct follow-up inspections to ensure installations are done properly.
Termimesh is installed where plumbing and electrical conduits or other service penetrations pass through the slab, under slabs, at cold joints or cracks in concrete and within hollow wall voids. It can also be wrapped around the base of wooden utility poles and fence posts before they are inserted into the ground. Instead of a complete sub-slab termite shield, the mesh can be attached as tight fitting "sleeves" around pipes before the concrete slab is poured. The sleeves are positioned on the pipes so that they are encased in the concrete when it is poured, effectively preventing termites from tunneling up the sides of pipes to enter a structure. Stainless steel clamps are used to ensure a tight fit around pipes. The mesh can also be glued to concrete surfaces using "termiparge," which is a solid cement-epoxy resin bonding material. Although it is best to install mesh before the slab is poured, to a limited extent it may be post-construction retrofitted using "termiparge."
A limited warranty is offered with Termimesh that covers materials and workmanship. This is a 10-year warranty, and there are no annual inspections or payments required. However, regular structural inspections for termite activity are recommended.
Termimesh must be installed properly to avoid any breaches where termites can find a way around the mesh. Because the outside perimeter of a concrete slab is not protected with mesh-sleeve installations, regular exterior inspection for termite activity is needed. Termites may enter structures by tunneling up the outside of the concrete slab or through a crack or crevice not protected by the mesh.
Lenz and Runko (1994) tested Termimesh in Australia. Untreated wood was encased in the mesh and buried at two locations infested with several species of termites. After three years, termites did not penetrate through the mesh, and encased wood was not damaged. Non-protected wood surrounding mesh-encased wood was damaged by termites during these tests.
Termimesh was tested at the University of Hawaii (Grace et al. 1996; Grace and Yates, 1999). Wood encased in the mesh was placed in traps used for collecting termites in field test sites that were heavily infested with termites. After two one-year tests, the termites were not able to penetrate through the mesh to reach any of the protected wood. However, Hawaiian researchers and Australian researchers (Lenz and Runko , 1994) have noted that the edges of the Termimesh need to be carefully sealed.
Termimesh was also field tested by Dr. Brad Kard (Kard, 1999; Kard, 2003) when he was with USDA Forest Service in Gulfport, Mississippi. The mesh was installed as a sleeve around in-ground wooden posts, around the base of hollow concrete blocks containing wooden blocks and as a complete "termite shield" under small concrete slabs with wooden blocks in a center inspection port. After 10 years, termites had not penetrated through the mesh in any of the field plots. Non-protected wood in the same field sites continued to be severely damaged by termites during these tests.
Grace, J.K., J.R. Yates III, C.H.M. Tome & R.J. Oshiro. 1996. Termite-resistant construction: use of a stainless steel mesh to exclude Coptotermes formosanus (Isoptera: Rhinotermitidae). Sociobiology 28: 365-372.
Grace, J.K., and J.R. Yates III. 1999. Termite resistant construction and building materials. Proceedings of the 3rd International Conference on Urban Pests (W.H. Robinson, F. Rettich & G.W. Rambo, Eds.). Czech University of Agriculture, Prague, 19-22 July 1999. Pp. 399-406.
Kard, B. M. 1999. Mesh may fit in as a termite barrier. Pest Control 67(2): 50-53.
Kard, B. M. 2003. Integrated pest management of subterranean termites (Isoptera). Journal of Entomological Science 38(2): 200-224.Lenz, M. and S. Runko. 1994. Protection of buildings, other structures and materials in ground contact from attack by subterranean termites (Isoptera) with a physical barrier -- a fine mesh of high grade stainless steel. Sociobiology 24: 1–16.