Liquid products control termites for at least five years when applied according to directions. The actual length of control on a structure will depend on many factors. Thoroughness of the application, environmental conditions, and density of termites in the area. If termites swarm again and continue to be a problem the year after treatment, it’s usually not a problem with the product. Termites have found an untreated gap in the chemical barrier. Termidor is still the leader with 11.5 years on average.