Subfloor repair help -- WITH PICS!

Please check these two pics out:




In preparation for a hardware floor installation, after pulling up the lino in this half bath I noticed water damage to the subfloor. I have removed one "panel" as can be seen in the first picture as best I could. I actually used a cut off tool w/ 3 3/8" wood saw blade attached to cut inside the toe kick, and get closeish to the wall.

First question: I will try to get as close as possible to the wall (right hand side of image) with this saw, but i'll probably still be at least 1/4" from it. I think I should have almost half of the underlying joist exposed. Is this good enough? Any tips on chopping out that last inch or so of subfloor next to the wall? Chisel? (chiselling plywood sucks...)

The second pic shows a better view of the water dmg. The joists look to be in good condition and apprently didn't suffer (much) from the water. This pic really just shows a better view of the difficulty I'm having removing the subfloor.

Second question: I'm not well versed with the way doorways are put together -- I'm guessing I'll need to remove the trim from the door jamb, right? Also I'm guessing that the subfloor is one entire piece under the (interior) wall. Is this correct? Is cutting the subfloor out from around the (interior) wall acceptable?

FWIW I decided taking out the vanity would too much of a PITA. Is this OK?

 

It looks like your there to me. I'd be more worried about how wet that insulation is.

That wood will dry if you get a fan on it. Right now it looks like you cut it pretty good, and you have something to nail the patch plywood into and have support.

 

If you are that worried that you won't have enough nailing surface, just nail (screw) blocking perpendicular to the joist. As far as leaving that 1/4" wood near the wall, you will just have a trickier cut with the new subloor. Just measure carefully. I once replaced a floor that was hardwoon and extended under the wall and was a pain! to remove. I would take off the doorjambs unless you feel you can slide the new piece under it?...seems like more work......If the new floor is higher than the old floor you will need to cut a little off the bottom of the door jamb....I would remove the vanity but I don't think it is necessary.....As long as the floor is level and secured.

 

Insulation is dry as a bone -- this was a very old water stain from what I can gather, as it certainly didn't happen while I've owned the home (3 years).

Upon inspection of the piece I removed, the underside of the original subfloor ply is clean and dry, so it looks like a minor amount of water was introduced.

I'll try to clean up the edges a bit, in the mean time.. off to the hardware store to rent a floor sander and buy a chunk of plywood for the patch..

 

I managed to get this far this afternoon.



Should I go ahead and try to cut out (from below) that chunk of subfloor under the short door wall? I think I could slide the replacement plywood underneith..

 

All your plywood joints need to be supported. Its easy to add stringers between the joists to do this. Screws are your friend. You cannot leave plywood edges unsupported. I would trim that jag and run a 2 x4 (or better) right under that door jamb. That little extra 1/4" is not worht worrying about. Just add a support board like bsmtdweller said.

 

Here it is after removing the ply "outcrop", and adding a stringer:


I managed to tidy it up from below (thankfully I have a massive *walk* space underneith this floor...)

 

much better