Hardwood sleeper floor on slab

acerunner

ok, so hardwood floor on concrete is a big no-no due to moisture wicking up from the concrete into the wood and warp it. That I understand.

What about if hardwood is installed on a sleeper floor, thus spacing it up about 4~6"? How far off the concrete would hardwood have to be?

tacomahardwood.

hardwood over concrete is a bad idea for a DYI . I don't do it here in washington state because of the rain and risk , . BUT the first thing is to make sure all gutter spouts drain away from the house . And test the concrete with a calcium chloride test kit . DON"T do this job with out a calcium chloride test , And really i say don't put hardwood over concrete . Another BUT , you could use a engineered floating floor , or there is traffic master vynil , thats ok over any floor and looks pretty good , If you REALLY want hardwood over concrete get some one that has training and knowledge in the area you live in or don't do it . Hardwood over condrete is a huge risk . tacomahardwoodfloors.com

acerunner

i havent done a calcium chloride test, but I've done the test where you tape a small sheet of vapor barrier to the concrete and check for a moisture after a few days. The floor does get visibly damp. I guess I will have to quantify that with a calcium chloride test. But that's direct contact with the slab. Would it be the same issues if raised above the stab with sleeper floor?

Gary in WA

http://www.buildingscience.com/docum...ms?full_view=1

Be safe, Gary

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acerunner

thanks gary. I've seen the article before. But it seems they are referring to flooring that's directly on the slab. I currently have sleeper floors. So i guess my question is, does being 5" above slab make any difference? I guess there would need to be some ventilation in the 5" space for it to work right?

Before starting this project, I actually had plans to use the dimpled plastic membrane as vapor control as described in the article. I was going to use Delta-FL on slab, then xps foam, then plywood, and then any flooring I want. But after starting the project, I realize the slab is not level (sloped for drainage) and the sleeper joists are shimmed (I'm sure painstakingly) to compensate for the slope. Leveling the floor is a much bigger job than I want to do, so I was trying to find a way to reuse the sleeper floor.

Also, the article mentions an epoxy to seal the slab, but no product details. Do you know what those products are? I've seen epoxied garage floors, but I don't think that's the same type of epoxy.