I've been pulling moulding and trim off and on for a few days for an upcoming custom closet install. The community was great in helping me to figure out ways to get the trim off the wall. I've discovered some oddities with the subfloor and wanted your opinions.

Is it normal for these types of gaps and holes to appear on the subfloor of a hardwood floor? The closet is on the second floor but there seems to be considerable gaps between the drywall and edges of the plywood. The wall that this sits on is an exterior garage wall. I'm concerned that this is a sign of a problem with the subfloor that should be fixed. Are these holes and gaps anything to worry about, aside from vermin and pests? Can I seal them with expanding foam, do I need a flooring contractor to come fix this, or is this relatively normal?

Thanks again for your help.

Plywood IssuePlywood Issue 2strong text

  • 1
    Relevant: diy.stackexchange.com/questions/222675/…. That third picture looks like it was chewed by rodents but I would expect more leftover debris so it could just be damage from the original install. Those boards look like nothing more than filler so you should be able to use foam backing rod, caulk, silicone, or expanding foam however you desire.
    – MonkeyZeus
    Apr 21, 2021 at 14:23
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    How thick is the finish floor? It looks like underlayment, not subfloor. Subfloor will go under the walls typically, unless the house is old and is balloon framed, then the subfloor will meet the wall as seen in the picture. Then it would not be plywood... The damaged piece is not rodent damage. It was damaged by a fork lift or careless dropping before the install
    – Jack
    Apr 21, 2021 at 14:28
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    Jack, that would make an answer I'd endorse.
    – isherwood
    Apr 21, 2021 at 15:13
  • Thank you for all the answers. Great ideas and suggestions! Learning a lot on here.
    – Todd
    Apr 22, 2021 at 1:03

1 Answer 1


Vermin would be my only concern. Spray foam is not the best sealer for the critters but staple some steel wool over the opening and put the spray foam on that.

The foam encapsulates the steel wool using less foam and critters don’t like chewing on the steel wool (they will tunnel through spray foam very quickly).

Those gaps look larger than I like but as long as your trim covers the edges there is nothing to worry about, possibly a rodent highway under the trim if not filled but no structural issues.

  • 1
    Great answer as usual, Ed. Steel wool is a great deterrent and being held in place by spray foam is an awesome idea. Again, I learn something here every day. Thanks + Apr 21, 2021 at 15:02
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    Copper wool is sold to prevent rodent access because it does not rust. Apr 21, 2021 at 21:19
  • I like the idea put forth. I'll probably just use the copper wool and not double it with the spray foam after reading the comments here and then gandering at the relevant thread linked here. Thanks everyone.
    – Todd
    Apr 22, 2021 at 1:20

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