I'm interested in installing a wood floor in my Dallas area home that's built on a concrete slab. My concern is that some of the tiles through the center of the house show signs of movement in the foundation. There are also some minor cracks in the drywall around that area.

I've had a couple of foundation folks look at the house and they don't feel that the issue is significant enough to warrant foundation work. They suggest improving drainage and such around the exterior which I've been trying to do.

My question is; What wood floor installation method would work best for me? I've considered a floating floor, but want something more solid. My latest thought is putting down a floating plywood subfloor and then nailing the wood floor to that. Would this provide a more solid and less hallow sound?

Has anyone had experience with installing a wood floor over a foundation that's had slight movement?

Thanks for any advice!

Hmmm. I've never heard of a floating plywood floor. Not sure that would even work, especially if you have some cracking and unevenness.

Anyway, there are a few important considerations before you do anything.
1. Is the floor sealed?
2. Is there a moisture and humidity issue? make sure this won't be an issue, otherwise, this will be pointless
3. Is your floor even? If not, I would consider leveling it (e.g. use self leveling cement).

Assuming you've taken care of 1, 2, 3 and assuming there are no height issues, then I would install plywood subfloor (w/ hilties) for most secure installation and then nail the hardwood into that. That's your most secure option - not the cheapest and not the easiest, but definitely the most secure.

Debbie Gartner aka The Flooring Girl
http://TheFlooringGirl.com
Westchester County, NY

I believe the 3 items you mention taken into consideration.

With regard to floating plywood, I've heard that some installers will first put down a vapor barrier, then put 2 layers of 1/2" plywood over the vapor barrier with upper layer going in the oppisite direction of the lower layer. The two layers of plywood are screwed/nailed together, but they are not fasted to the concrete. The wood floor material is then nailed/stapled to the two layers of plywood.

I'm wondering if this technique would do two things:

1) Give the hardwood floor more of a solid feel when compared to a floating floor that's floated directly over the concrete.

2) By not fastening the plywood, I'm hoping that there will be a little more give if there's any movement in the foundation.

Any thoughts would be greatly appreciated.

I think your on the right track. I have never done the floating subfloor, but other installers on this site talk about it all the time, and I will do it when the situation calls for it.

Here's a bunch of photos of one I did with an awful solid beech prefinished from Mullican. First off the wood had dried down to much and many planks were off in width by an eigth of an inch. The slab was awful and cracked to begin with. Had to grind it flat, patch cracks, moisture test (ASTM F 2170 AND ASTM F 1869) , MVP4 with plastic. Did I mention it was below grade and the Mullican tech guy said dont do it. Well its still there. Personally I'd rather do the two layers of half inch or 3/8 ply instead of the one layer of 3/4 ply. The only reason I took on this job is because the guy accepted my outrageous quote. And his tile guy tried gluing it direct and failed.

Go left to scroll through the photos.

http://www.flickr.com/photos/13772863@N08/5478630869/

A simple "sleeper system' would work quite well. Whether it be a furring strip or 2x4.
The 2x4 system can have a rubber cleat fastened to the bottom for a softer floor system.
Dan