subfloor over concrete for hardwood - Contractor Talk - Professional Construction and Remodeling Forum

ssh · 04-12-2009, 08:06 PM

Looking for advice on products to use over concrete floors in basement to install hardwood flooring.Customer insist on subfloor before finish floor.

mhillc · 04-12-2009, 08:15 PM

use 1/4 inch foam board then 3/4 ply screwed to the concrete then finish floor . It cuts down on the celing hight a little bit but its what i always do.Hope this helps.

**ChrWright** · 04-12-2009, 08:18 PM

Quote:

Originally Posted by ssh

Looking for advice on products to use over concrete floors in basement to install hardwood flooring.Customer insist on subfloor before finish floor.

I'm curious why they are "insisting" on this?

ssh · 04-12-2009, 09:01 PM

customer wants to see something put down before hardwood for nailing.

ssh · 04-12-2009, 09:05 PM

would you use a dow fan fold and then untreated plywood fastened with tapcons?

Floordude · 04-12-2009, 09:48 PM

I wouldn't put a nail down solid wood in a basement!

You need to think about a floating engineered, seriously. As the replacement will be on your wallet.

**ChrWright** · 04-12-2009, 10:30 PM

Quote:

Originally Posted by Floordude

I wouldn't put a nail down solid wood in a basement!

You need to think about a floating engineered, seriously. As the replacement will be on your wallet.

True that...

**loneframer** · 04-12-2009, 10:36 PM

HD stocks a product that is OSB over a plastic waffled base, comes in a 2'x2' T&G. One Tapcon screw in the center of each panel will suffice in most cases. It is designed to go over concrete, the waffle design allows air movement underneath. I know of one person who put it down under carpet in a basement with good results. I'm considering it over a slab to do a laminate floor in my own home.

ssh · 04-13-2009, 07:55 AM

customer is a true woodsman-from hunting to interior finish.the basement is a 3600sqft. man cave w/11ft.ceilings.everything has to be wood and stone.laminate is out of the picture.looking for the right products without problems in the future.

**ChrWright** · 04-13-2009, 08:16 AM

Quote:

Originally Posted by ssh

customer is a true woodsman-from hunting to interior finish.the basement is a 3600sqft. man cave w/11ft.ceilings.everything has to be wood and stone.laminate is out of the picture.looking for the right products without problems in the future.

I'd be very concerned about any solid hardwoods installed below grade. 3600 sq ft is a lot of wood to replace if there are problems. It's hard to tell from afar what the moisture situation is in this house and location. I've worked in houses with deep deep basements with cobwebs in the sump pits year round. I've also seen others with pumps that run nearly non-stop even in the driest part of the summer.

How old is the concrete? Sump pumps--do they run often? Are dehumidifiers in use (preferably tied to the HVAC system)? What's the RH in the basement on a dry day vs. a rainy one?

Even if it's fairly dry--I'd still recommend an engineered floor vs. solid. And if it's marginal hardwood may just be a bad idea.

jciotti7 · 04-13-2009, 08:29 AM

Maybe flagstone. That should fit with woodsy interior and eliminate moisture concerns.

wannaBelkhuntin · 04-28-2009, 10:31 PM

Quote:

Originally Posted by ssh

Looking for advice on products to use over concrete floors in basement to install hardwood flooring.Customer insist on sub floor before finish floor.

I used this product on a project I just finished. DeltaFL [I am not allowed to post a link]deltafl.com
This went down first and then screwed 3/4 T&G plywood with tap-cons every 2 feet and then laid 3/4" T&G Maple with 1 1/2" nails with an air assisted flooring nailer. I researched this and posted questions on some other forums I visit. This seemed to be the best solution, and now after installing the DeltaFL I believe it is a very good product.
Good Luck Dave

thom · 04-29-2009, 01:13 AM

Why not a floating floor, similar to a jazzercize floor. 3/4" ply on heavy rubber pads that float on the concrete floor with a standard 3/4" maple strip floor on top.

macatawacab · 04-29-2009, 02:21 AM

I agree with ChrWright about concerns AND here is one you should be concerned with............what installation system will the manufacturer warranty? If you go outside the published system criteria for this installation you will not get anywhere with the manufacturer.

For this install I would be very concerned about my risk management.

floorsavior · 04-29-2009, 05:19 PM

I would use the ashphalt cut moisture barrier first then , install 1x3 sleepers 11 on center for a basement nail down job. Go to the NOFMA website and read about the cut-back moisture barrier and sleeper system. It has been effective for over many years

ian@prosource · 04-30-2009, 09:40 AM

you could try using these products from Sika,

Sika Primer MB Epoxy-Based Moisture Barrier, to deal with any possible damp issues,
then use Sikabond-T54 Solvent-free Polyurethane Adhesive or Sika Bond- T55 low VOC Polyurethane Adhesive,

the adhesive is flexible so it can cope with expansion & contraction, this allows engineered & solid wood to be used above & below grade, they put a warrenty with their products.

Sika have had these products used for over 1 million sq yds, they are also widely used throughout europe,

Tommy Hilfiger have this as their approved installation method in all there stores in canada,

Sika also do a stick down method that also uses a sound proofing underpad (Sika Acoubond) for use with concrete floors in condo's

all these methods are designed to do away with the old methods of laying a ply subfloor first and nailing down the wood floor, they also solve the problem of reducing the height of the room.

Not able to put their link up so just google sika, or sika.ca, or Sikacanada.com they are a world wide company so you should find them ok

Floordude · 04-30-2009, 03:13 PM

Ian, in a basement environment, it is not only the substrate moisture but the under ground humidity, that says solid is a really bad idea.

Sure you speed down that road everyday, but tomorrow, Johnny Law is there and gives you a ticket.

ian@prosource · 04-30-2009, 04:06 PM

Working on the basis that if they are looking to put solid wood into the basement, the area will be fully developed and will get regular use/ poss even a Bi level, with this in mind the humidity in the area should be controlled much like the rest of the home and should not cause too much of a problem.

I have found that it is only in the USA & Canada that people shy away from solid wood below grade, Europe and other parts of the world do not seem to have a problem as long as they use the correct materials and preparation, of course as with most flooring products (not just wood) the manufacture states that the area should maintain temp & humidity between normal levels,

Have a look at this link to see just how far solid wood has come, 18 mil solid oak laid as floating floor with a easy click system.

W w w. hardwood-floors.uk.Com/solid hardwood

Sorry but not able to display full link

mrghm · 05-01-2009, 01:19 AM

Quote:

Originally Posted by ian@prosource

Sika also do a stick down method that also uses a sound proofing underpad (Sika Acoubond) for use with concrete floors in condo's

we use skia products the sika acoubond is a great idea but it has failures in Aust. When we use this product we lay 3/4 ply over the acoubond then lay flooring.

the failure's have occured when hardwood / engoneered was direct laid over the acoubond and the adhsive it uses is ridged drying and causes issues with movement.

ian@prosource · 05-01-2009, 02:38 PM

I am a little surprised to hear that, the adhesive is meant to be laid into wet (it has a short open time) and when set it should be semi flexible not ridged, what did Sika say about it when you told them ?