I am putting up a structure and I have reached this stage where I got to apply some termite treatment. My Dilemma is,is it really necessary.? The foundation,has a 4 foot layer of hadcore (because the topsoil was black cotton soil.) and as far as am aware,termites cant chew through hardcore and reinforced concrete,Plus most chemicals have a toxicity span of 5 years,10 years,the most.

Whats the rationale of protecting a building in its first 5 years when its in excellent (youth)condition,then 'doing nothing' (chemical Treatment) when its 10 years or more?