Gregg Henderson | 7/29/2006 12:54:38 AM
Homeowners in South Louisiana and elsewhere in the Gulf South who are rebuilding after last year’s hurricanes have opportunities to add more termite protection to their homes, according to experts with the LSU AgCenter.
"Piers help homeowners be aware of termite activity," Henderson said. "Because the building is off the ground, you can see their shelter tubes very easily."
Both Formosan subterranean termites and native subterranean termites live in nests in the ground. In order to infest wood in a building, they have to move from the soil into the structure through shelter tubes that protect them from exposure to daylight and other elements.
Because Formosan termites also can build nest structures in other places if they have wood and moisture available, they are able to survive without returning to the soil, Henderson said.
To infest a raised structure, the termites must travel up or through the piers or any other objects connecting the building with the ground, according to LSU AgCenter entomologists. Since the underside of a structure built on piers can be completely accessible for inspection, termite shelter tubes can be visible and detected before serious damage has occurred, the experts say.
Henderson said piers made of concrete blocks should be capped by solid concrete or a metal shield to prevent termites from moving from the ground into the building without being seen. Termites can move undetected through the spaces on the inside of concrete block or masonry piers, and experts advise even solid concrete piers should be capped.
The LSU AgCenter’s termite experts said wooden posts treated with creosote can be effective in holding off termites, but eventually the critters could find their way through the insides of the posts. That means such posts should be capped, too, Henderson said.
"Caps don’t prevent termites from entering a house," Henderson said. "But the caps cause the termites to expose their shelter tubes for visual identification when they try to get into a building."
Piers in wind zones also need hurricane strapping or other connections, said Dr. Claudette Reichel, LSU AgCenter housing expert.
"Termite shields of solid metal flashing or stainless steel mesh capping the entire pier and extending beyond it all around are needed to force termites to reveal themselves," Reichel said. "But these shields should be of a compatible metal with any metal connectors that contact it."
Hurricane straps or connectors may need to penetrate the termite shield, which can create a hidden termite entry point, Reichel said. That means any holes need to be properly sealed with a suitable epoxy.
"This may be easier with a steel mesh termite shield than rigid metal flashing," she said.
Reichel said another issue is the corrosiveness of copper-treated materials. "Any metal connectors, termite shields and fasteners should be either double-hot dipped galvanized or stainless steel."
Henderson warned that infestations of pier houses can be traced to only a few common entry points in addition to the piers. Any wood-to-ground contact provides an entry point for termites, he said. And any discarded wood or other cellulose products left under the building following construction can provide food for termites, as well.
Other entry points include sewage lines, electric conduits and other lines in contact with both the house and the soil, Henderson added. These should be treated and inspected.