solid or engineered hardwood on moisture prone concrete slab?

The previous owner installed Pergo in my house. It is now warping due to moisture from the slab. I have done all I can to deflect water away from the slab (gutters, drain pipes, etc.), but the moisture persists. I want to replace it with something that will not be adversly affected by moisture. From the little bit of research I have done, it appears that solid hardwood is probably the best next to ceramic tile but I do not want ceramic tile. Engineered hardwood seems to be the cheapest and easiest to install.

I want something that will hold up to moisture and last a long time.

Any advice appreciated.

tia,

Ross

 

No flooring is going to stand up to this kind of a moisture problem and a solid hardwood is going to fail if the laminatre did. You need to address this first before you install a new floor.

 

What kind of underlayment is there underneath the Pergo??
Did you run a plastic sheet test to check moisture content of your slab?
If your slab is too moist, any hardwood is doomed to fail.
It may be a bit more work & $$$, it'll be worthwhile to put a plywood subfloor before installing any hardwood floor to your current slab foundation. As you read thru many previous posts in this forum, you'll encounter numerous horror stories with warped floor on slabs.

Bandages don't last forever.

 

Anything wood is going to be effected and eventually show signs of failure, even the plywood masterjoe suggests.

Any moisture and a wood product, don't mix.

 

>You need to address this first before you install a new floor.

I did "address" it but still have the problem. I live near Houston. The climate here is somwhat tropical - high humidity and lots of rain. I'm starting to think that mosture in the slab is just a fact of life here. Even if I did get rid of it I'm not convinced it wouldn't come back.

>What kind of underlayment is there underneath the Pergo??

Pergo 6 mil plastic sheet and Pergo foam stuff.

>Did you run a plastic sheet test to check moisture content of your slab?

Yes this is how I know there is a moisture problem.

Thanks for your replies. I think I'm going to try to solve the mosture problem. Any ideas what I can do? The worst problem is on the north side of the house that the sun never sees. That side is also a constant battle with mold/mildue on the brick.

Maybe I should just go with ceramic tile...any thoughts?

Thanks,

Ross

 

There are a few possibilities -

1. Glue down 1/2" exterior plywood using urethane hardwood flooring adhesive (ie. Bostik Ultra). Then glue and screw second layer of 3/8" plywood to first. The urethane adhesive is a proven moisture barrier and you are not "puncturing" it with nails. Downside is you have to have 100% glue coverage, slab has to be flattened to insure good adhesion with plywood, and it's a mess to work with this. You would use a standard rosin moisture barrier above plywood as second layer of defense.

2. Prep slab and apply mastic adhesive then 6 mil poly then mastic adhesive followed by 2 layers of plywood as above. This method is described in the NOFMA guide although I don't think it's done much anymore because of todays hi tech glues. I believe NOFMA suggests this method for high moisture areas.

3. Laydown 6 mil poly on slab followed by 1/8" foam (as used in flotaing installs) then float 2 layers of ply on this. In this case I'm somewhat skeptical that poly will not be abraded through by rubbing on the slab but who knows?

In all cases layers of plywood are used in case the glue fails (underlayment integrity is maintained). Best to run ply joints at 45 degrees to strip direction.

As additional insurance, you could apply polyurethane to the underside of your strip. This would slow down moisture absorption and even out stresses in the wood helping to prevent gaps and crowning.

Of course don't use any of these methods w/o professional advice because I don't have experience with these methods in your application/area. There are also many details I have left out.

I would seriously look into hardwood vs. tile. Yours may not last 100 years vs. some in an arid part of the country, but who cares? A large part of my house is tile and it's just not a nice surface to walk on barefoot - cold and hard and I'm not the type to wear slippers.

Good luck

 

How did you address your moisture prob,raharold?
There might be more to it than just grading and roof water management. If you have a failure in the vapor-barrier beneath the slab, the only way to address that problem is to first find out if that is the problem. If you have a serious vapor emission level going on,blanketing your floor with plastic will only delay another inevitable failure.
Were I in your shoes, I would look for a reputable waterproofing contractor. Tell them your needs and cross-reference what they tell you with what the floorcovering manufacturer of your choice has to say. That,in my opinion,is your only sound starting point.
Many people in the floorcovering trade can tell you whether or not you have a vapor emission problem,but their valuable advice often stops there.

Chuck.

 

>There are a few possibilities -...

Thanks for the input I like the first option but I'd leave that to a professional...if it comes to that.

You are right, tile may be my best option. I'm kinda leaning that way now. Maybe some granite tile in the formal areas.

>How did you address your moisture prob, raharold?

By diverting as much runoff from the roof away from the foundation with gutters and drain pipes. Also, I don't know if this is a factor but the side of the house where the problem exists is on the north side so it doesn't see any direct sunlight near the foundation. Next to the foundation is a bed of ferns then a concrete driveway.

>If you have a failure in the vapor-barrier beneath the slab, the only way to address that problem is to first find out if that is the problem.

I have no idea what is between the foundation and the soil. It's a 37 year old house.

FYI, a friend of mine who lives in the area has original hardwood foors in his 55 year old house. The construction is hardwood planks nailed to strips of wood that are bonded to the concrete foundation with some sort of tar like stuff that resembles roofing tar. Is this a standard method? He has had no moisture related problems. Maybe he is just in a drier area.

Ross

 

I see their are many professionals here that I know offering professional advise. Here is some more advice I think you should read.http://www.vaportest.com/Webpages/Va...onHomePage.htm

 

I had a hardwood floor in Houston. It was a Bruce engineered hardwood laminate. very expensive, done in herringbone pattern. We had problems all the time we lived there with pieces popping up. Houston is just a problem area for that. Especially if you live in one of the areas that floods... HOuston is the humidity capital of the world. Nothing you can do to stop that except to move.

Mine was glued (mastic) directly to the slab with the substance you describe at your friend's house, and yes, this is what they normally use. My wife had some furniture sitting on it in an office, and it trapped moisture, rotting the pieces, and requiring replacement. We kept putting new pices down, and then Bruce stopped making the flooring. Not good.

We investigated all forms of answers, and discovered only two answers that seemed realistic. One was to put a subfloor with an air-space for ventilation (still seems like you'd get mold unless you forced air through it), and CERAMIC TILE. The area that we had with ceramic tile never had a problem. The subfloor would, of course give you a transition problem as well.

Go to the Expo store out by Willowbrook Mall in Houston. I'd be shocked if you didn't find a type of tile or stone you could learn to like. It's a high-end store by Home Depot and has a zillion tile and stone types- many installed for you to see. The store's worth a visit even if you don't buy anything.

 

check out www.sealflex.com

 

I edited my description of my frineds flooring above. He has a space between the floor and the concrete. This is the type of construction I was considering.

Thanks for the replis snapple. I think we are going to go with tile, If I can talk my wife into it.

Ross