Adding another layer of plywood to an existing plywood subfloor should be relatively simple. Well, everyone agrees you don't line up new sheets on old, but overlap seams. But you can either nail/screw to joists or not, use glue or not, nail/screw every 3 or 4 or 5 or 6 inches at the edges, and nail/screw every 6 or 8 inches in the plywood. Too many choices for someone who just wants to do this once, and not have to go back because he's picked the wrong thing. I guess the more nails/screws the merrier (the more the sheets will be held together), but what's considered too few? Gluing would certainly give more strength. Nailing or not nailing to joists? Why or why not? And if, in one sheet (to another) you accidently do hit a joist and skip fixing it, how bad is that?
- posted
17 years ago