Q&A: Do Termite Shields Work?

A.Termite shields are breeders of false confidence. Termite shields do not prevent the entry of termites, but supposedly force the termites to build a tube around the shield, so their presence can be detected during an annual inspection.

According to conventional design, an effective termite shield is a piece of metal flashing that projects at least 2 inches below the woodwork on each side of the foundation, with the outer edge bent down at a 45-degree angle. All joints and openings, such as around anchor bolts, must be sealed. But because of porch and patio slabs, interior finished walls in basements, and other house details that interrupt the barrier, I have never found a house fully protected by termite shields. Soil poisoning is the only effective protection against subterranean termites I know of.