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Hardwood flooring over concrete slab

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Jan 21, 2014, 09:31 AM
Hardwood flooring over concrete slab
I am planning to install hardwood floors in my living room. The room is a slab on grade and I already know that it pitches to the center. I would like to use 3/4" thick hardwood that is nailed in and not glued. I belive that I need a 1.5" nail at most otherwise it will hit the concrete.

My question which method is best for leveling the floor:
1. Self-leveling cement and then plywood or
2. just 3/4" plywood with shims.

Next, should I used a trowel on vapor barrier or just felt paper for the underlayer between the wood and concrete?

Thanks for your help.


This message has been edited. Last edited by: Frankie_t,
Jan 31, 2014, 09:32 PM
Your best option is to use a floating floor...
Me personally.. I would never just use plywood over concrete only and expect the nails to hold.
Jan 31, 2014, 10:52 PM
Frank, I don't know what part of the country you live in, but in cold climates that slab can be very cold. Part of my house is on a slab. We have laminate with foam backing covering it, but the floor is still very cold. So, if you live in a cold climate, I'd be looking for ways to create a warm floor or, at least, a very well insulated one.
Feb 04, 2014, 06:07 AM
What would you be nailing to? You would have to level the floor to within 1/8" before installing any kind of floor, so if your pitch is greater than that, you would have to correct that with a self-leveling grout before doing anything else. Then you would have to put something down to nail to, and as ron45 suggests, plywood on concrete is iffy. I would tend to agree that a floating "engineered" wood floor is your best option.