How to lay a h/w floor on concrete slab.
redandrote
| Posted in General Discussion on
A friend wants to have a true hardwood floor laid over concrete slab – is this possible and if so what is the least expensive and practical way to lay a well constructed floor.
Any help will be most appreciated – Simon3
Replies
Good question, but I have not done one like that yet. I was interested to see what responses you got on this one, but no luck yet.
there are some nice prefinished hardwood floors with adhesive backs you might be able to stick down. theres probably going to be issues with moisture coming up from the concrete though. don't know how you will get a moisture barrior down and then stick wood to it.
don't know if it would be practical where you are talking about, with head room and step up, but maybe lay down a low profile joist system of sorts on the concrete to nail the tongue and grove on top of.
best I can do for you right now, maybe someone else will jump in on this one.
2 ways to go with this. First is you glue down the hardwood with an adhesive made for this. This becomes your vapor barrier. Try Bruce hardwoods(part of the Armstrong Co.) or the NOFMA websites for details. The second would be to lay 3/4" plywood down with tapcons or rals and then nail down with shorter 1 1/2" nails. Guess it really depends on your finished floor height and how much adhesive you want in your hair.
Hi Wango - Thanks for the answer - I guess I'll give the glue down a try - the ply would really take it up high. Your help is very much appreciated. Simon3
Simon,Good choice, going with the glue down. I've installed hardwood over concrete using 3/4" plywood underlayment and this works well. Just be sure to use nails that penetrate the concrete fully when laying this ply down. Also be sure to use a vapor barrier over the concrete first. I used 15lb felt. Also make sure your hardwood nails do not come thru the back of the ply or you may be lifting your subfloor up.
The glue is amazing stuff, turning into a tough rubbery bond. What I don't know is how to get the floor all pulled up tight when there are no nails. You may need to buy one of those pulling devices used for laminate and floating flooring. Don't get wacky warped hardwood in this case.
good luck.
I like the idea of using P.T. 2x4 sleepers on their side with an osb or plywood base. I would use some 1 1/2" Rigid foam between the sleepers to seal and insulate it. If you can spare the room, try covering the floor with the rigid foam first so you don't have any thermal bridging. Then place some regular 2x3 kd spruce over the rigid and use either 4" nails in a ramset, or tapcons to secure them. Then install your subfloor and hardwoods. The insulation would keep the floors at a more consistent temp. giving less of a chance for expansion and buckling.
I would think that by putting plywood on top of felt paper you could create condensation buildup between the two, causing rot.
Just a couple of ideas.
Rob
Edited 12/3/2004 7:44 pm ET by Rob
I don't know whether my thank you went out - but to my great delight the problem is solved - she is going with carpet.! Simon3
back again, just found this one for you on construction techniqes...
http://forums.taunton.com/tp-breaktime/messages?msg=50761.2
Skip the real hardwood. Go with floating engineered laminate over foam. I have never seen real hardwood over concrete that didn't develop problems eventually. Squeeks are common within the first year.
Laminate has come a long way and the price is right too.
Gord
St.Margaret's Bay NS
is this possible
Certainly is.
Welcome to BT.
You picked a great question to get our feet "wet" here.
Look at a product called Dricore itsa a snap together osb panel with a layer of pvc under it with stand off dimples to allow air flow accross the concrete floor . You could then install your hardwood on top of the Dricore.