So- when I pulled up the carpet and padding to prep my subfloor for new bamboo flooring, I noticed that the plywood has some large water stains on it. This doesn't bother me that much, except that there are a couple of small places where it's warped a little, and when I pried up the tackless strips, I noticed that a lot of the nails had rusted, so the plywood is splintering when I pull up the nails. The plywood is about 1" thick, and appears to only be one layer- and, naturally, some of the subfloor extends under walls into other rooms. My joists are about 4' apart.
So, a couple of questions:
Do I have to replace the entire subfloor in the room, since it all seems to have been exposed to water, or can I just deal with the pieces that are warped? Also, since I can't pull out an entire 4 x 8 sheet of the plywood, due to it running under a wall, can I replace just a small section of the piece? The other problem is that where the nails rusted is right next to the wall- do I need to do something about that?
And then- how do I go about any of this? Any advice I can get would be appreciated
Subfloor is usually 3/4 plywood or OSB, but could have an additional layer on top. You can replace a bad section by cutting at the joists, and adding a 2x4 at the seams for extra support, you don't have to replce the whole piece.