I just bought a new house, and the subfloor is very squeaky. The subfloor is 3/4" tongue-and-groove OSB which has been nailed down on 19" spaced joists. Luckily, I am changing the carpet to wood flooring so I am free to fix the subfloor prior to installing the wood flooring.
I complained to the builder about the squeaking, so they screwed down the OSB using deck screws everywhere at 6" intervals. It definitely helped the squeaking, but unfortunately many small squeaks remain. The superintendent tells me that wood structures will always squeak and that this is normal. I don't believe that; there has to be a way to fix those squeaks. Besides, the squeaks are quite noisy and I think it's unacceptable.
I really hope the problem isn't in the joists themselves as this would seem a difficult problem to fix. Is it possible that the squeaks come from the tongue-and-groove joints between the joists? I've read somewhere that it's possible that the T&G joints have not been glued properly and that this can cause squeaks. If that is the problem, is it possible to simply push glue down the joint over the subfloor, or do I really have to remove and replace the subfloor?
What else could cause these squeaks?