How Often Should a House Be Treated for Subterranean Termites?
How often your house should be treated for subterranean termites depends on the strength of the termiticide used, the severity of the problem, and how vigilant you are about regular inspections to ensure the termites don't return. Commercial termite killing chemicals come in two grades.
Termiticide Grade 1
This lesser grade will need to be used every three years, as long as it is applied correctly. There are several mixtures available for DIY anti-termite chemicals, and there are a few common mistakes that come with these. Often, too much water is added and/or the termiticide is not applied deeply enough under the house foundation. Keep this in mind if you plan to go this route.
Termiticide Grade 2
This stronger chemical will need to be used every five to ten years, and it is only available from a professional pest-control service. This is recommended for more serious infestations, and your house should definitely be inspected once a year after the first treatment. This termiticide creates a poisonous barrier in the soil; this in turn kills or repels the subterranean termites. It also needs to be applied to exposed wood and empty gaps under the house, especially in more humid climates.