Like HowStuffWorks on Facebook!

Termite Foundation Damage

Termites can quickly do serious damage to your foundation, or to the structures that make contact with it.
Termites can quickly do serious damage to your foundation, or to the structures that make contact with it.

If you live in Alaska, this needn't concern you. If you live in any other U.S. state, you face the possibility of termites invading your home, and if they get in through the foundation, you're looking at potential structural damage that'll cost you an arm, a leg and a lot of sleepless nights.

Your degree of risk hinges on a number of factors other than where you live. The type of foundation your house is resting on plays a significant role in how easy it is for termites to tunnel through in search of food.

That food, of course, is wood, so in most (but not all) cases of termite damage to foundations, it's not the actual foundation material that's damaged. Most foundations these days are made of concrete, and termites don't eat concrete. Instead, they squeeze into cracks in the foundation and build a tiny, insidious city that can threaten your house's substructure.

Poured-concrete foundations, especially rebar-reinforced ones, are the most secure, but even they can have cracks. Concrete-block foundations are less termite-resistant; in those, there's the added issue of mortar, which often has more cracks and is easier to burrow through and weaken.

Once inside those cracks, they build mud tunnels. These tunnels protect the worker termites as they make inroads into your home. The termites can slowly widen those tunnels through extensive use, putting pressure on the cracks in the foundation and causing weakness in the structure itself. But that's mostly if you don't catch the problem for a long, long time.

The more immediate risk, in the case of concrete foundations, is to foundation-adjacent components, such as floor joists and other structural supports, which typically are made of wood. Also, foundation access can offer direct lines to food sources like porches and basement window frames.

That's concrete. But there's another type of foundation that can suffer more immediate and dramatic problems with termite infestation. The pier-and-beam foundation, which you see in homes with crawl spaces, supports a home on an all- or mostly-wooden substructure, offering termites a food source in the foundation material itself.

As in the case of any type of termite problem, there are treatments for foundation infestation and damage, including installing termiticide barriers in the soil surrounding the foundation, treating any foundation-adjacent wood with pesticides, and drilling into the actual foundation to inject pesticides into cracks and holes. These approaches can also be used as preventive measures, or pre-treatment, which reduce the risk of a problem in the first place.

Regardless of your foundation type or the extent of damage, this is one of those cases where you want to bring in a professional. Termites aren't the easiest pests to deal with, to put it mildly, and your home's foundation is probably not the place to be learning as you go.

Or, take a huge loss on the house and head to Alaska, where termites dare not roam. Look out for the cockroaches and bed bugs, though: They're not afraid of the cold.

For more information on termites, home damage and foundation treatments, check out the links on the next page.