Q: I had hardwood floors installed last spring. We noticed within a few weeks that the seams were rising, creating a wavy effect. Our flooring contractor advise us that this fall when we begin to use the heat it will correct itself.
It has not. What do you think?
A: Wavy hardwood floors? It sounds like your boards are cupping, leaving raised edges. This only happens in abnormally high moisture situations. The installer should have checked that the sub floor was within 4% moisture content of the flooring, and ideally the floor itself should have had a reading of 7-9%. It is particularly important also to leave an expansion gap along the side walls in case the floor expands from too high humidity or an actual water leak which would cause the floor to swell and press against the walls. I think your contractor should first come and put a moisture meter on the floor to see how it reads now. If it is within normal range but hasn’t flattened out it may need to be sanded flat. However, sanding such a floor while it still has high readings will likely cause the floor to crown, and then the middle will bow and be higher than the edges.