I structural elements are the wood members, than borate-based spray is what you want. Some examples are Tim-bor, Boracare. As the patent is off, there are now others as well. Look at the active ingredients; you want something that says “disodium octaborate” or close to that. This is a wood treatment only.
If soil treatment is to be done, I like the active ingredient “Fipronil” a lot.
What part of the country are you in? Would you be targeting subterranean or drywood termites or both? That will be a major factor is chemical/treatment choice.