I have an 80 year old detached garage located in s. fla. That I am converting into an apt. It is wood frame stucco. Like nearly every older structure I have worked on in the last 30 years there are dry wood termites. I have seen a few where the stucco and wire lath are the only thing supporting a significant portion of the second floor. I would like to slow them down, or otherwise deter them. If I err it will be on the side of non-toxic to humans Vs. death to all insects I'm familiar with them, they eat slowly compared to the subs , the plumbing in walls is cpvc which has restrictions in its use around certain chemicals. I've researched boric acid, (toxicity about same as table salt), thinking of drilling small holes in studs and injecting with boric acid solution. Any thoughts out there on this?

Once you have termites in a wooden structure the only way to halt the destruction is to hire a professional exterminator and pony up with the price as doing it yourself is basically useless. If you value the garage, do it right or the entire structure can come crashing down one day. Termites are insidious and eat non stop. I had termites in my duplex in Ft. Laud and paid a small fortune to get rid of them professionally, but it was well worth it as they never came back.

Digging holes, boric acid is only going to give you a false sense of actually doing anything.

The best way is to have it tented and properly fumigated professionally as the bugs have totally eaten their way into the structure itself and can't be reached with boric acid.

By the time you notice termites, they have more than likely weakened the integrity of the structure.