The barrier is only affective against burrowing, but termites don't start new colonies by burrowing. They swarm (usually once annually)... fly off and build new

The barrier is only affective against burrowing, but termites don't start new colonies by burrowing. They swarm (usually once annually)... fly off and build new colonies. If only the method described here actually worked, we'd save billions of dollars a year in damage.