Unlike subterranean termites, drywood termites do not need access to the soil. If they have established a nest in your home, the only reason drywood termites will leave the colony is to start a new colony (termite alates or swarmers).
Since infestations can be hidden or difficult to access, drywood termite treatment options are limited. The most common methods include structural fumigation (gas), heat treatment and direct wood treatment. Alternative options may include extreme cold and electronic methods.
Structural fumigation is the preferred method to exterminate drywood termites that have established a large colony or more than one nest in a house. Fumigation also may be recommended in situations when it is difficult to find the termite nest, or the nest is located in an area inaccessible to direct wood treatment. Since fumigation is an extensive process, other methods are typically attempted first for termite control.
Structural Fumigation for Drywood Termites
During the fumigation process, your home is enveloped in a tent. A fumigant (gas) with the active ingredient sulfuryl fluoride is introduced into your home to reach all areas where termites may be living.
Fumigants can pass through porous wood and reach into the smallest crevices in between wood in your home. Brand names for sulfuryl fluoride fumigants approved for residential termite treatments include Vikane, Master Fume and Zythor.
Heat Treatment for Drywood Termites
Before heat treatment, your home is covered loosely covered with a tent. However, instead of introducing a fumigant, your treatment expert will use a system of propane heaters and ducts to blow hot air inside your home. These heaters, sometimes combined with fans, will raise the temperature of your home to between 120 and 140 degrees Fahrenheit.
By raising the air temperature, your expert also raises the temperature inside wood to 120 degrees Fahrenheit. Since termites cannot control their own body temperatures and require moderate temperatures to survive this extreme temperature will kill all termites and their eggs.
Similar to gas fumigation, heat treatment does not provide any residual protection against future infestations. Heat only controls active termite infestations.