Expert: Dave Johnson - 1/12/2008

Question
How level does the subfloor have to be to install a solid hardwood floor? I have a 4 ft level when I set it down I have maybe a eighth inch gap under the level.  Is this ok or is this too much gap? Also how much expansion gap do I have to have at the wall edge? I'm installing this in the winter.

Answer
Hi Bob,
Expansion; if your baseboard is going down after installation, leave 1/8" where base will be, at places where fits will be exposed (door stools, trim)fit as tight as you like.
As far as floor level goes, 1/8" in 4', is no problem.
You should put some paper (red rosin or felt) under the new work, this will prevent squeaking between the old and new wood.
If you have concerns about any imperfections in the floor level, you could also "shim" a low area by adding a few more pieces of the paper.