Termidor SC is not really meant to be used as a crawl space wood treatment. If you are going to be applying Boracare, it is not necessary to also use Termidor. Boracare will penetrate completely into the wood and will remain active for the life of the wood.
Termidor SC is a great choice for termite treatments. It lasts 10+ years in the soil if applied as directed. I have included a termite article below for additional information on treating around your structure. If you are going to be treating the wood in the crawlspace, we recommend that you apply Bora-Care if treating for drywood termites.