Newly installed oak wood floor is cupping

Q: We had 1/2 white oak installed in our dining and kitchen area to match the 40 year old oak floors. The contractor did not acclimate the new wood at our site. It is now cupping, but the old floors are not. Do you feel like he should replace the flooring?

A: I think you need to determine why the floors are cupping, which is a clear indicator that the moisture in the wood has risen sharply since being installed in your house. Why would that be? Do you have a leak some place? Is this over a crawl space that is very wet? It couldn’t be so humid in your home at this time of year. Some measurements need to be taken to find out where all the moisture is coming from.

Similar Q: We had new oak floors installed in summer 2016. After about 7-10 days we noticed planks lifting in one area. After about 4 weeks it was up to 15 planks lifting. In addition, the entire floor is cupping. The installer believes it is all due to too much moisture in house. However, the new hardwood floor replaced an old hardwood floor. Never had any issues with the old wood floor. In addition, the other rooms in the house on same floor with new hardwood floor are also hardwood, we’ve never had any cupping issue. I think it is a installation problem. What do you think?

A: If the floor is heaving and cupping this is a sure indicator of a moisture imbalance. It sounds like the floor is under pressure. Somebody should come in and check with a moisture meter. 7-9% is normal. Any reading significantly above this will create a problem.

Follow-up Q: Thanks. We tested moisture in different parts of the floor. Again every plank appears to be cupped. The floor is about 700 sq feet. The monitor reads moisture levels all over the map. Anywhere from bone dry to 15%. I asked that the manufacture of the floor be called in to inspect. Anything else I can do?

A: It is always a good idea for the sub floor and floor to be installed are tested with a meter for moisture content. The sub floor should not be more than 4% higher than the floor to be installed. I don’t know if this was done. I don’t know how high the humidity is in the house. But generally cupping where the edges of the boards are curled as opposed to crowning where the center of the board is raised is from the moisture coming from the underside of the floor. This isn’t a new house is it?

Follow-up Q: Not a new house.

There are rooms (den and office) under the floor with new hardwood floors. We have custom wood furniture in that first floor room and custom wood crown molding. Both are about 5 years old. No warping or sign of moisture problem. The new hard wood floors replace older hardwood floors. Older floors were perfectly straight even in summer months.

A: It is bewildering because if the new flooring was poorly stored and not protected before delivery to your house and it had unbalanced moisture content it likely would have shrunk and produced gaps after being installed in your place. I would have the manufacturer send a rep and perhaps if you can contact an inspector from the National Wood Flooring Association they can find the problem.