The defining characteristics of an Eichler home—siding, beams, and exposed ceiling decking—are without a doubt tempting targets for visiting termites. The good news is that termite treatment methods available today can be highly effective, and common-sense action on the part of homeowners can reduce the chances of termites deciding to make your home their home.
Any wood structure is of course potentially susceptible to termite invasion, but according to Don Petree of Able Exterminators in San Jose (408-251-6500), "Because Eichlers have a lot of exposed wood, they are more vulnerable than the average home."
Subterranean termites are one of three types of termites that can damage homes; the others are drywood and dampwood termites. Termites can be visually distinguished from ants on close examination by their straight antennae; thick waists; and for those with wings, front and hind wings that are the same size. (With ants, hind wings are smaller than the front, antennae are bent, and waists are narrow.) Don't be misled by assuming that all termites are white; they also can be tan or black, just like ants.
As their name implies, subterranean termites live underground and require moist environments. Petree claims that Eichler radiant heat systems can attract subterranean termites with their warmth, and tubing leaks attract them by increasing the moisture level in the soil (yet another reason to have your radiant system pressure-tested for leaks each year!). From nests in the soil, termites can build 'shelter tubes' above ground—in particular along vertical sides of foundation footings—to penetrate into wall spaces.
The western subterranean termite (Reticulitermes hesperus) is the most destructive termite in California, according to the University of California Pest Management Program. Eradicating them is not easy. As his preferred method, Petree now uses a new pesticide chemical that is injected through a rod two feet into the ground, all around the perimeter of the house. It contains a bait that attracts the termites, as well as chemicals to kill them. Because the pesticide is released only below the ground, it is not a danger to people or pets. Traditional approaches use above-ground baits and insecticides, and consequently regular monitoring is required.
Drywood termites are able to tolerate very low wood moisture levels for prolonged periods, remaining completely above ground in nests that do not connect to the soil. For these reasons they can attack not only walls but ceilings as well. "Homeowners only tend to notice them when they see their droppings," says Petree about the tiny, elongated pellets about 0.03 inches in length, varying considerably in color. When detected, responsible exterminators will first attempt localized treatments and not rush into an expensive whole-house fumigation project.
Treatment methods include freezing and microwaving, but Petree prefers the 'electro-gun' method, which uses a portable device, easy to maneuver, that creates a very intense electromagnetic field over a small area. Fumigation with Vikane gas for a 24-hour period is the answer if the termites are suspected to have invaded a broad area. The state requires that rated houses are tested to ensure that the gas is gone before the house is re-occupied. This entire process takes two to three days.
Dampwood termites are not commonly found in Eichler homes because the typical subdivision environment does not provide favorable conditions for them. The Pacific dampwood termite (Zootermopsis angusticollis) is almost one inch long, making it the largest of the termites in California and relatively easy to identify if spotted.
Sometimes carpenter ants are confused with termites. These ants do not actually eat wood, but tunnel into it to make their nests. They often nest in trees or telephone poles and then send out scouts to find new nesting sites, resulting in them entering homes. Carpenter ants can be difficult to control because their nests can be outside the homeowner's property. To truly eradicate them, nests must be located and destroyed.
Eichler owners can do their part to combat termites by ensuring that there are no direct paths from soil surface to exposed wood, and that all wood is properly painted or stained. Using caulking, seal any gaps or cracks through which termites might enter. Keep sprinkler systems oriented away from the house to prevent siding rot, and don't let vegetation come into direct contact with exterior beams and siding.
Discourage dampwood termites by removing any rotting wood from your property, including old tree stumps and fallen branches. Finally, inspect the foundation and all exterior surfaces of your house on a regular basis.
For more information online, see the U.C. Davis website.