Podcast Short: Why is My Wood Floor Cupping?

In this excerpt, the team troubleshoots a cupping floor and gives recommendations on how to avoid this issue in the future.

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[a-a-ron]

I worked on a 27 unit condo building, each unit was 2, 800 to 4, 800 square feet. Priced from 2.3 to 4 million each. We had two Amish trim Carpenters who would only order 20 ft length of trim. We're talking 8 inch baseboard 12-in crown molding. These guys were so good you didn't have to putty or sand anything... The superintendent had the air running the whole time with the doors and windows open. The units were 99% completed punch list were about 65% completed. One Friday afternoon the superintendent's right hand man thought it would be smart to turn all the ACs down to 65 close all the doors and windows, lock the units for the weekend. Monday morning they tried to blame all the damage on the painters... Cost of contractor 400+K to fix.

[loumonte]

Great episode.
My oak flooring cupped (2-1/4) due to moist basement. I though I could avoid it by waiting a couple of months before the sanding. No such luck though.

[StumperTX]

Good snippet overall, but shouldn't installing the floor "too wet" actually *prevent* cupping? Wood swells as it takes on moisture, so you are installing it "bigger" than it would otherwise be. I would expect gapping rather than cupping if moisture was too high on install.

[craigkeller]

Install the floor, sand the floor, finish the floor, the back unfinished side picks up atmospheric moisture and swells leading to the nice cupping effect. Wood moves people. It’s alive.

[tillman]

Cause the dog keeps going on that spot

[coldfingersub]

Finish the backside of the board facing down to slow down or stop the moisture penetration the same as the face
insane idea but it works. And it’s a lot of extra work.