EXT wrote:

I normally add a piece of support plywood subfloor material between the
joists with cleats attached to the joists to keep it in place, plus screws
and some construction adhesive, then cut a patch of more plywood the same
thickness as the original subfloor cut to fit into the opening, again
screwed and glued down to the support plywood. This way your floor is flat
and well supported.

"Tom" wrote in message
...
I recently added additional floor space to my exisiting kitchen. In
the process several large and small holes were left in my old sub
floor as I moved kitchen plumbing to the new addition. My question
is, how do I best repair the holes in my subfloor so that I can lay
either a laminate or hard wood floor over the holes?

I normally remove all of the old subfloor, plywood isn't that expensive.
I then do any insulating or other work while the space is accessible if
it's a finished space below, then install new subflooring with plenty of
construction adhesive to prevent any potential squeaks. The time you
spend cutting and fitting patches eats up any savings in the cost of new
plywood.