"Marsha" wrote in message
ups.com...
We have an addition on a crawl space. The crawl space is about 3'
high. Underneath on the ground is rock dust with plastic sheeting over
top. The spaces between the joists are insulated.

We had hardwood flooring put in the addition. Within about 6months the
planks are cupping. It's very slight but it is noticable (at least to
me). What is causing this? Everyone I've asked always says "is their
plastic underneath covering the rock?" the answer is Yes. Then they
don't have any other ideas.

Does anyone out there have any idea what caused this? The worst
cupping is going on in the entry part of the new addition. There's a 6
foot opening to walk through. The flooring right in this obvious area
is the most noticeable. Most of the room is covered with an area rug.
What's under the area rug looks ok.

Thanks,
Marsha

Where do you live? Do you use your air conditioner? Regardless of the
plastic under the crawlspace, is it moist under there? Was the floor nailed
down or glued down?

My parents are struggling with a similar problem with a new hardwood floor.
Their crawlspace is bone dry. The flooring installer and the manufacturers
rep both blamed crawlspace moisture, which seems to be their attempt to
dodge the problem. Personally, I believe the installer goofed (he glued the
floor down, which is completely against anything the manufacturer
recommends). A bad situation which may need to be settled in court...

KB