Hardwood on concrete

[Kunta Kinte]

Since i've got some 3/4 hardwood which I can't use upstairs, I was thinking I could use it downstairs. The area I want to use it in has

2/3 new construction slab, 1/3 old construction. the new area is on grade, the 1/3 is partially below grade (on one side). (the ground slopes from the old to the new.)

Is the issue with hardwood below grade strictly an issue of moisture and subflooring?

Anybody know a good site/link for (successfully) installing 3/4 hardwood on slab?

thanks, B

[Robert Allison]

Try any of the hardwood flooring sites. They will have their specs for installation over concrete. Here is the one for Armstrong:

It requires either a layer of 3/4" plywood, or sleepers installed onto the concrete. Depending upon how you do that, you would install a moisture barrier in conjuntion with it, either above or below.

Then install the flooring on the substrate.

I don't know of any hardwood flooring manufacturer that will warranty solid HW floors directly onto concrete.

[smith_bp101]

Yikes! If you want hardwood on a slab, you'll need to install the engineered hardwood. Otherwise, I would suggest installing 3/4 ply with a moisture membrane if you install solid.

[Edwin Pawlowski]

Sorry, it is not recommended unless you take special steps, like putting insulation and vapor barrier between 2 x 4 sleepers. You lose a lot of headroom that way and a PITA in places. You can use engineered hardwood though, along with the proper barrier.