Although there are several types of termites in the United States, subterranean termites are most common. They are found in every state except Alaska. They attack more homes and cause more damage than the other types of termites. Because of this, most termite control using termiticides is done to stop subterranean termites.
Subterranean termites live in the soil. In nature they attack dead trees and stumps that are near the surface of the soil. They attack homes by moving up into the structure and eating the wood, cardboard, and paper products that they find. Termite control using termiticides creates a barrier in the soil to keep the termites from reaching the home or other protected structure.
Since the 1980’s, scientists have found a variety of new termiticides. The new products kill or repel termites more effectively than the old petroleum–based products. Some of the new termiticides are very repellant to termites. When the termites detect the termiticide in the soil, they turn away.
Other termiticides are non–repellant. The termites move through the treated soil without detecting the termiticide. The termites pick up some of the termiticide on their bodies. As they move around in the colony, the affected termites pass the termiticide to their nest mates by physical contact in the colony.
The termiticide barrier in the soil keeps the termites out of the home. The barrier must be applied uniformly so there are no gaps. It is important to be sure that there is the same amount of termiticide in the soil all around the structure. If the barrier has gaps, termites can squeeze through and enter the building.
Around the exterior of the building, a shallow trench is usually dug next to the foundation. The trench is seldom more than a few inches wide. The purpose of the trench is to hold the liquid termiticide and prevent runoff.
If the footer of the foundation is close to the surface of the soil, the treatment only requires putting the liquid termiticide into the trench. The termiticide label prescribes the amount of termiticide that is applied. If the footer is deep in the soil, the technician injects the termiticide into the soil with a hollow rod until it reaches the footer.
Houses with crawl spaces would normally be treated underneath the crawl space. The trenching and treatment process in the crawl space is similar to the outside treatment. All of the piers are treated in the same way.
Many homes have concrete slabs against the foundation. These are often porches, patios, and garages. In these cases, the technician drills holes in the concrete. Termiticide is injected into the holes to form a barrier next to the foundation. The holes are plugged and sealed with concrete after the treatment.
If the foundation wall is made of bricks or concrete blocks, it is often necessary to drill holes into the blocks to allow treatment. A small amount of termiticide is injected into the holes to treat the void spaces inside the blocks.
Homes that are built on concrete slabs have openings in the slab for pipes to enter. The termiticide must be applied under the concrete near all of these openings. The technician drills a hole in the concrete near each pipe penetration. After treating each hole with termiticide, the technician plugs the holes and patches them with concrete.
It is common to use a foam–generating machine for treating these pipe penetrations. The machine changes the liquid termiticide into foam. The foam spreads under the concrete and helps ensure that there is a complete barrier around each pipe.
Modern termiticides will protect a home for several years. The exact time will vary because of weather, watering, and the type of soil. To be sure that the home is free of termites, many homeowners have their home inspected annually.