Replacing Plywood Panel in Subfloor

RichardZ · 12-15-2012, 05:43 PM

I'm down to the subfloor in several rooms in the home. In one room, there's one subfloor board (4'x8') that's rotten, and fortunately, doesn't run under any walls. I plan on taking it up, pulling out any remaining nails, laying down Loctite's PL subfloor glue, and then screwing a new board in its place.

Question: what's the spacing for the screws going into each joist -- every 6", every 8", every 12"?

Also, in another room, I want to get under the subfloor and don't want to damage the ceiling on the other side (way too much demolition). Can I do the same thing, except rather than putting down new plywood, simply re-lay down the old-but-good plywood?

Thanks,

Richard

joecaption · 12-15-2012, 05:48 PM

Every 6" to be safe.
By the time you dig out the nails in the other panel it's going to be pretty tore up, just replace it.
Why does it need to come out?

JazMan · 12-15-2012, 08:56 PM

Subfloor plywood is t&g. Might not be easy to remove it and re-use again. Be sure to install blocking along the long sides (between joists) to compensate for no more t&g, and/or add a sheet of underlayment over the subfloor.

Jaz

RichardZ · 12-15-2012, 09:12 PM

JoeCaption, thanks for the info. I presume 1-5/8" screws every 6" will do the trick?!?

JazMan, I only wish it was T&G. This was built 55+ years ago, so it's straight plywood. I like your idea of blocking along the long side -- I'll keep that in mind for when I come across such an instance in the future.

I will be adding underlayment, if I can every figure out exactly what that translates to. I've been told to avoid luan. Would 1/4" SandePly work? How about a 1/4" "hardwood" plywood like birch? Could I use a fiber mat?

Ultimately, the finished floor will be a loose-lay (aka, floating) sheet vinyl.

Thanks,

Richard