Termites? Oh No!

Termites are almost everywhere, and termite damage is rarely covered by homeowner insurance. That's a bad combination, because termites cause $2.5 billion/year of property damage in the U.S.

Termite problems potentially get worse the farther south and west you live. Homeowners and builders in Maine, North Dakota, and Alaska: you can stop reading here and go brush up global warming, because otherwise, you will probably not have to deal with termites. Others: read on.

Aardvarks aren't native to the U.S., and they aren't easily domesticated, so that leaves four practical ways to prevent and control termite damage:

1. Build it right

2. Maintain it properly

3. Treat with chemicals or baits

4. Add termite shields

The first two fall under the category of prevention - always the best and least expensive solution. Stay away from the chemical solution if you can. These chemicals are toxic and can reach the groundwater.

Build it Right

Most termites enter through the foundation, so any cracks and gaps must be completely sealed. Remove any debris from outside the foundation before backfilling, and use clean backfill. The foundation should extend above the finished grade. After backfilling, fine grading and landscaping, no untreated wood should be in contact with the soil.

Add a termite shield (a thin termite-resistant plate) between the foundation and wood structure or framing. Any seams in the shield should be soldered or otherwise sealed. If your foundation has outside insulation, put a termite shield along the top of the insulation. Termites will tunnel through insulation to get to wood.

Termites love moisture, so don't encourage them to visit. The ground should have at least a 5% slope away from your foundation.

Maintain it properly

Keep moisture and termite food away from the house:

• Maintain that exterior grade to drain away from the house; even if you change your landscaping.
• Clear sticks, branches, leaves, and other items.
• Fill depressions that might hold water. This will keep water flowing away from the house (and it will minimize the mosquito problem).
• Adjust landscaping sprinklers to ensure that the house is not being watered along with your lawn and garden.
• Make sure splashblocks are in place at downspouts, that the splashblocks are in good condition, and that they still direct water away from the house.
• See if there is leakage at your hose bib (outdoor faucet) when you are using a hose.
• Inspect/replace the washers on your hoses periodically. Water from leaking hoses can run straight down your foundation wall.

Treat with chemicals or termite baits

Chemical treatments to the soils around the foundations act as a shield against termites. Several different types of chemicals can be used and the method of application is particular to each chemical, but these are usually the areas of concern:

• Soils along foundations and crawl spaces
• Soils under appurtenances such as attached slabs and porches
• Soil around plumbing or wiring penetrations

Chemicals have limited effective lives, so many homeowners maintain a contract with a pest control operation (PCO). These contracts usually include initial treatment, annual inspections, and reapplication as necessary. Find a reliable PCO in your area through the National Pest Management Association (NPMA). Find out more about termite chemicals and baiting, including contacts for more information about specific chemicals and application techniques, in PATH's Technology Inventory.

Add Termite Shields

Proper placement and installation of physical barriers can provide termite protection for houses with little to no risk of pesticide exposure to the occupants. Shields of various types - aggregate, stainless steel mesh, and plastic impregnated with a termiticide - are placed between the foundation and any wooden structures, as described above, but they can also be used at other vulnerable spots in the house perimeter. Find out more about this type of non-chemical termite control in PATH's Technology Inventory.

For more detailed information see Chapter 6 of PATH's Durability by Design.

Content updated on 8/4/2006