How to spot repair damaged plywood subfloor

Q: I have a beautiful engineered floor which was glued down to a plywood subfloor. Unfortunately, 4 contiguous strips need to removed due to damage. The epoxy which was used is resulting in a bond which is pulling up some of the subfloor and producing both an uneven surface to start with and probably rendering the “tongue” and groove system unusable as the old floor is bonded to the adjacent tongue and groove as well.

My thought was to sand down the subfloor to an even depth, replace with the appropriate thickness of plywood and then use epoxy to bond the replacement pieces to the new base. I would not be able to use the tongue and groove however. How would you repair damaged plywood subfloor?

A: I think I would have tried to sand/scrape the damaged boards and restain/finish them as a first attempt, depending on the damage of course. However you are past that point now. I’ve repaired a couple of such floors though polyurethane adhesive was used, not epoxy. Very tedious work. You need a sharp chisel to carefully bit by bit remove the boards and use the chisel to clean up the plywood. You could use polyurethane adhesive for the repair and if the chunks ripped out of the plywood aren’t too severe, perhaps you could just fill the voids with adhesive. Otherwise you have to also cut out the plywood and glue new pieces in. After you get through all this and place the replacement boards down you will need to put something heavy on them until the adhesive dries. It sounds like you are handling it as best you can. There isn’t a magic cure at this point. Just a lot of tedious and careful fitting.

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