Termites That Damage Cement

As is the case with many household pests, control methods for termites sometimes include urban legends that are passed down from generation to generation and that range somewhere between pure myth and pure fact. One such urban legend is that termites are capable of eating concrete. Consulting some expert opinions can reveal whether or not this myth has any value and can help improve termite control methods to better prevent damage to your home.

The Myth

Some homeowners believe that termites are capable of eating concrete. The origin of the myth likely lies in the fact that termite-infested homes are very often built on concrete slab foundations; and termites live in soil beneath the foundation. Upon discovering that termites travel through openings, cracks and crevices in concrete slabs, homeowners sometimes conclude that the termites must have eaten their way through the concrete to reach the wooden parts of the home.

The Science

According to the University of Florida Extension's termite fact sheet, termites do not eat concrete. The defensive fluid soldier termites use to erode wood has no effect on concrete. The cracks, crevices and openings in concrete through which termites travel are more likely due to natural cracking or shrinking of concrete over time. Sometimes the openings are there by design -- openings that allow utility lines to run through the concrete slab and reach the home, for instance. Under these conditions, it is only a matter of time before termites foraging in soil find the openings in concrete and travel through them to infest a home.

Concrete and Termite Control

Even though this myth is only a myth, it can provide some useful ways of augmenting a termite control program. For new homes, treating the soil underneath a concrete slab with termite insecticide can prevent foraging termites from moving through the concrete slab after it cracks. For existing homes, examining accessible concrete parts of a home for termite activity can help determine the origin of a termite colony, a determination that's key to achieving total termite control.

Other Considerations

In addition to treating the soil underneath a concrete slab with termite insecticides, several other methods are available to prevent termites from moving through concrete in a new home. Use crack-free concrete, if possible; and avoid using hollow-block, brick or rock foundations, as these materials provide numerous passageways for termites. A foundation made of these materials can be insulated from soil-borne termites with a 4-inch or larger buffer of concrete between the soil and the foundation. Most important: Avoid wood-to-soil contact whenever possible.

References

• University of Missouri Extension: Subterranean Termites; Richard M. Houseman
• University of Florida IFAS Extension: Formosan Subterranean Termite; B. J. Cabrera, et al
• University of Florida IFAS Extension: Subterranean Termites; P. G. Koehler & C. L. Tucker
• North Carolina State University Extension: Termite Control; Michael Waldvogel