Expert: Daniel Humphrey - 2/2/2008

Question
I plan on installing a  solid hardwood floor in a room 10 by 10. When I put a 7 ft straight edge on the floor I have a gap about the thickness of a nickel under the staight edge on one joist. This joist must be a eight inch lower. Is this a problem, should I try to build this up with rosin paper since I'm laying paper first? What do you think?

Answer
Bob,

The hardwood will easily span low spots up to about 18 inches across. Just don't nail in those low spots! Your idea about putting extra paper there might work out well and won't hurt a thing.

If the low spots are greater than the distance between regular joists, you can fill those low spots in with very thin strips of wood cut on a table saw, about 1-1/2 inches wide and as thick as the low spot. With regular wood glue, fasten the wood strips directly to the subfloor directly lined up with the joists, then cover with the single sheet of paper. Mark on your paper where the strips are, so you can nail through them.

Hope this helps. Good luck with your project. Hardwood floors are one of my favorite things to do.

Daniel