Hardwood floor installation musts

Don't rely on felt for a level subfloor

Q: I just read a column of yours on do-it-yourself installation of hardwood flooring and have a question.

I noticed there was nothing in the article about making sure the subfloor was level beforehand, just that the homeowners chose a nail-down stick floor and they stapled a layer of building felt to the subfloor.

So is it just floating floors that need to have an absolutely level subfloor? Or does the building felt "absorb" any difference in level, so to speak?

A: The subfloor doesn’t have to be dead level, but it must be flat. That means no bumps, ridges, nooks or crannies. These imperfections must be sanded flat or filled. This holds true whether the flooring material is solid wood or laminate.

Wes Clark and his wife Hui Ping live in a 20-year-old house in a hilly area of Castro Valley, Calif. Bill helped with the installation. Although they didn’t put a level on the floor, we’re certain there had been some settling over the years, resulting in a slight slope one way or another.