Wood floats

May 9, 2011 10:53 AM

We are buying a one-story 1959 ranch-style home in Austin, Texas. The floors are 70% polished concrete (which is just the top of the slab). I want to add wood floors and our contractor is suggesting that we float the engineered wood floor on the slab.

We'll be adding wood to about 1100 square feet and will be adding cork to the kitchen area. I originally wanted to use real hardwoods, but have since learned that is a Bad Idea on a concrete slab in our area (and the height added by the install would be unworkable). So I'm looking at pre-finished engineered wood floors, which are much more stable with regard to moisture. The slab appears flat and is in good shape. The majority of the wood will be placed in a large L-shaped combo living/dining room area with a long straight run (about 40 feet), which will be the first thing you see when you come into the house.

Our contractor is suggesting that we float the engineered wood floor on the slab, which I believe would mean adding a moisture barrier, and then laying the wood directly on top of that, so that it isn't connected to the slab. This is quite a bit cheaper than laying down plywood, which is nice. However, I'm concerned that the floors will either be noisy or that there will be some other issue that will make me wish I had done the plywood install.

Long way of asking -- anybody had any experiences, positive or negative ("Don't do it!"), from floating engineered hardwoods on a slab? We're planning to stay in this house a *long* time, so want to do it right (and I'm mourning that we can't use solid hardwoods).

posted by seventyfour to home & garden (12 answers total)

Floating engineered wood flooring is essentially PERGO with real wood as the laminate. I installed this type of flooring in a vacation house that I built for my parents. The slab also has a radiant heating system in it and everyone loves the floor. We rent the house out when my parents are not using it and the guests all ask about the floor because it's so nice. I think it's really your best choice, based on your description. We ordered the flooring from ifloor.com
posted by humboldt32 at 11:07 AM on May 9, 2011

I live in a 1947 slab house in central Austin, and the previous owner had engineered hardwood floors put in right before the sale.

Three years down the line everything is looking pretty good, and it doesn't creak. Some of the joints have slid around a bit, and we do have a few wide gaps, but its not disastrous.

The flooring came in big planks with a thin piece of foam glued to the bottom. Its slip-fitted together with no glue or fasteners.

Here's a pic of another room we installed ourselves from the same batch of material. Feel free to memail with any questons!

http://www.flickr.com/photos/bug138/1317700841/
posted by bug138 at 11:15 AM on May 9, 2011 [1 favorite]

You'll probably put down a vapor barrier and a very thin foam underlayment below the floating floor [assuming the flooring doesn't have the foam on it already, like bug138's]. [I used the foam, no vapor barrier, because mine is all on upper floors]. The foam underlayment will quiet the floor. I assume you're worried about it moving vertically and "bouncing" against the concrete.
posted by chazlarson at 11:16 AM on May 9, 2011

There are padded underlays that can be installed either as part of the moisture barrier or separately that provide some improved feel to the floor as well as a bit of insulation. The setup you describe is what I understand to be the "standard" setup for wood-on-concrete these days.

I put some engineered bamboo in my basement on the concrete and it's pretty nice. I used a combo moisture barrier w. padding and it's not noisy at all. It feels very solid and I didn't even do a very good job installing it.
posted by GuyZero at 11:19 AM on May 9, 2011

I went through the same decision process (also in Texas), and the general consensus was to float the floor. We have engineered floated wood and love it.
posted by texas_blissful at 11:20 AM on May 9, 2011

It's pretty much the only way people here in the UK lay engineered flooring, and concrete subfloors are near-universal here.

Provided the subfloor is (a) level, and (b) dry, you'll have no problems at all. A good moisture barrier/padding combo will only add a few mm to the depth of the flooring. Creaking tends to be more of a problem with timber subfloor, particularly in upstairs rooms where there's more movement in the floor. Having said that, I've got engineered bamboo over a moisture barrier underlay over an old wooden floor in my upstairs bathroom, and it's completely silent.
posted by le morte de bea arthur at 11:43 AM on May 9, 2011

I have engineered wood on concrete with a moisture barrier and it's great. I don't find it noisy, and it looks great.

I'd suggest you go for the best floor you can afford, with a good, solid base and a thick layer of wood. Mine was around £45 per square metre, but I think it was well worth buying at the top of the range.
posted by essexjan at 12:01 PM on May 9, 2011

I have a 1960 ranch house in Austin. I had bamboo installed directly on the slab.

I many rooms, everything is just fine. There is a significant amount of warp in one area of the living room, however, that has supposedly resulted from the contractor using improperly rested mastic.

So I'd look out for that. Make sure that all the glue is the same, is room temp, and has had a chance to rest.
posted by kaseijin at 12:15 PM on May 9, 2011

As someone who spent most of his life in the floor covering industry, this method of installation would be my number one recommendation for anyone with a concrete slab.
With a good quality sound deadener (in addition to the moisture barrier) it will sound much like a solid wood. You will notice a slight cushion under foot which you would not notice with a traditional nailed down solid wood installation.

If you would still like to consider solid hardwood, take a look at Sika's installation materials. I had a client who used Sika products to install solid hardwood in a penthouse condo and it worked very well.

Generally speaking, installing solid hardwood over concrete doesn't work well. Although there are some prefinished hardwood manufacturers out there that do allow their solid products to be installed over concrete, but you have to follow the installation guidelines perfectly.

Another consideration, if you decide to stick with engineered in a floating installation, but want to be able to finish the floor onsite, take a look at Owens Plank Flooring. It's a very well made engineered product that comes unfinished. It is, however, very expensive.
posted by nickthetourist at 1:05 PM on May 9, 2011 [2 favorites]

These are great answers, thank you, this makes me feel so much better, and is very helpful. It is nervewracking to be selling one house, buying another, and setting up renovations all in the same 6 week period....
posted by seventyfour at 3:13 PM on May 9, 2011

Nick: If I could bug you (and others on this thread) some more given your base of knowledge: do you have favored brands of engineered wood floors in the $5-$7 square foot range (not counting install, of course)? Favored suppliers? I'd love a deal but I've heard some offputting things about the lumber liquidators type outfits.

What characteristics would you look for in an engineered wood floor? We probably want oak, to remind us of the traditional Austin hardwood floors installed in the 1930s-1940s (and which are in our current house).

I've looked at the Owens Plank Flooring -- that looks ideal, but it is out of our price range.
posted by seventyfour at 3:20 PM on May 9, 2011

seventyfour:
The product line I'd recommend for you, that will do what you want it to, is Muskoka.
Look specifically at the Architectural Collection or the Solid Sawn.
Also, take a look at the Hardwood 101 section; some good basic info.

Oak is a common species, so pricing should be close to your budget.

I know very little about Lumber Liquidators.
The few bits of feedback I've heard have been mixed.

Feel free to message me through MeFi Mail with any additional questions.
posted by nickthetourist at 6:26 PM on May 9, 2011