I recently purchased a home and have found termite damage in an enclosed porch (porch is single story w/ flat roof). The original homeowners added a footer and extended an existing porch. Floor joists rest slightly above the old 6’ cement porch and span over dirt to the added foundation (cement block and sill). The home is roughly 40 y/o and over that time termites.found their way from the dirt into the ¾” plywood sub floor, hardwood floor and some of the wall framing. The floor joists are untouched by termites.and the wood does not “look” like pressure treated wood. The previous owner has treated for the termites.and they are no longer active.

I plan to treat the soil but would also like to protect the wood. I plan to use ¾” T/G plywood and will treat all wood with TIM BOR or termite Prufe. Would a coat of oil base primer on the wood, overtop of the borate treatment be helpful?

Thanks in advance for any help.