Expert: Dave Coil - 2/27/2004

Question
Hi Dave! We recently installed oak hardwood flooring in our bedroom. We "seasoned" the wood in the room for a week before starting the project. Almost immediately after completing and polyurethaning, we were startled by some loud "cracking" noises, and we have noticed some separation between a few of the strips. Can you tell what causes this? Did we do something wrong or is this "normal"? We are asking because we are so pleased with the appearance that we plan to do additional rooms and want to be sure that we didn't "goof".
Thanks! Sal and lin  

Answer
I can take a stab at this... was it a water based urethane?  The moisture content would allow minimal expansion, and the shrinkage of the urethane would then be reversing.  It is also a possibility that a few boards are warping... either back to where they were, if stressed during the install, or relaxing after having been banded or boxed under constraints.  Not every board will go down perfectly straight... (leading to more nails I hope,) and thus the moisture content of the urethane could give it cause to move.