Around the House
Depending on where you live, a soil pretreatment might have been required when your house was built. These treatments are typically covered by a multi-year warranty period, but problems can still happen, especially if structural changes are made to the home. Anything requiring breaking or cutting into a concrete slab or digging into the soil around the foundation of a structure can disrupt and even destroy the treated barrier. If you know your home was pretreated and you're thinking about remodeling or adding on to it, be sure to contact the pest-control company that did the original work. They'll keep your warranty intact by re-treating the soil.
The best way to prevent termite problems is before construction even starts. For all termites, using building methods and materials — pressure-treated wood or wood treated with borates — to minimize the chances for termite infestations is a good practice. Typical approaches where subterranean termites are a problem include treating the soil with termiticidal chemicals where the home is to be built.
Drywood termites will not attack painted wood; however, there is currently no effective treatment or method to keep them from entering through or under wood shingles.
Another proven method for keeping termites at bay is making life miserable for them.
Eliminating Wood-Ground Connections
Structural wood that touches the ground is prime real estate for subterranean termites, as it gives them quick access to the three things they need to thrive: food, moisture, and shelter. Take the wood away from the ground, and you thwart their access to each.
Make sure that wood products -- siding, latticework, door and window frames, and so on -- end at least 6 inches above ground level. If they don't, do what's necessary to create this clearance. It might require regrading the soil around your house or pulling soil and mulch back from the foundation of your home.
Other wood-abatement efforts that are effective for preventing both types of termite infestations include:
Storing firewood, lumber, or other wood debris away from the foundation of your house. Keep it out of your crawl space, too. Not only does wood stored in these locations provide a free meal for hungry little chompers, it also gives them an easy way to get into your home.
Remove all dead wood, stumps, tree roots, and so on from your property.
Use mulch sparingly, if at all. This goes for organic mulches like sawdust and wood chips as well as crushed stone and pea gravel. Termites don't find much nutritional value in mulch, but they do appreciate its moisture-retaining and temperature-insulating qualities. If you're going to use mulch in your flower or shrub beds, apply about 2 to 3 inches thick at the most. Never let it come up to wood siding or the framing of doors or windows.
Keeping Things Dry
As mentioned, subterranean termites are attracted to moisture. Preventing water from pooling around your home's foundation by keeping gutters, downspouts, and splash blocks in good working order is a key termite-abatement step.
Other moisture-abatement efforts for termite-control include
Repairing all leaking faucets (especially outside faucets), water pipes, and air-conditioning units.
Adjusting sprinklers and irrigation systems to keep the spray away from the foundation.
Grading the ground next to the foundation so the surface water drains away from the house.
Keeping the moisture in crawl spaces in check by removing leaves, dirt, and debris from soffit vents. If necessary, install additional vents.
Keeping Things Screened and Sealed
Installing screens on attic and foundation vents will help prevent drywood termites from entering through them. Also seal cracks and holes in window- and doorframes with wood putty.