Flaking, dull poly

Q: I have wood floors that have been refinished, stained and sealed with a polyurethane top coat. The poly has started to flake and is also dull. Is there a product I can use to revive the poly and reseal without having to sand it completely and reapply?

A: May I ask what was used as a sealer? If the finish is flaking, the only thing to be done is start over. The finish will flake from lack of bond between the top coat and what it sits on.

Follow-up Q: Unfortunately the previous owner did it, and I don’t know. It appears to be a polyurethane top coat that has dried up and is flaking. Do I have to sand off the poly and apply something else? or do I need to sand down to the stain, restain and reseal? I’ve seen some products that allow for a rough sand to dull the poly and then simply reapply 2-3 new coats. Just trying to figure out how invasive I’ll have to be, so that I only have to do it once.

A: It isn’t normal for a polyurethane to flake off. It can happen if there was a contaminant present, or if a previous coat of finish was not abraded well enough. If the source of the problem does not originate on the wood itself, you might be able to screen/abrade it really well to remove all the flaking and apply 1 more thin coat.