Gentlemen,

I have a concrete basement floor. About 30 years old. It's had carpet directly on it for all those 30 years. Today I pulled the carpet up - the foam underpadding came off like it was laid yesterday - not a hint of moisture. Except in one corner where I nkow that about once a year during a particularly wet rqainfall there will be a very small leak that gets in. (Small being enough to dampen the carpet, but it dries ina day or two)

Now I want to put down laminate flooring. So first, I need a sub-floor.

I'm thinking of two main options:

1) "Dricore" or any of the similar products out there. Basically, dimpled plastic sheet glued to OSB wth tongue & groove edges. They claim the dimples hold the OSB off the concrete to allow enough air flow that natural moisture will evaporate so you don't get mould under there. And theplastic protects the OSB from the moisture also.

2) Old fashioned sleeper subfloor. Lay 2x4's down on the floor on 16" centres with OSB over top.

So here's the main thing I've been thinking. If the 1/4" gap the very expensive Dricore stuff provides provides some miracle ventilation, then the cavernous 1 1/2" gap that 2x4 sleepers provides must be the nec-plus-ultra of sub-floor ventilation, no? The only difference is that the Dricore lainate moisture proof plastic to the underside of the OSB sheets. But how is that any different than putting a vapour barrier under the OSB on a sleeper floor? LEaves th esleepers in the damp area - OK, so instead of spruce 2x4's, you use the new plastic 2x4's for decks. There - a fraction of the price, better vantilation, equal moisture barrier.

Anyone see a fundamental flaw in this? Experience?

Thanks.

 

what does the laminate manufacturer reccomend? can the laminate be glued directly to the concrete?

 

I like your idea of the plastic 2x4's with the vapor barrier under the osb. But I don't see any reason you couldn't rip the 2x4's in half. Save a few bucks and floor to ceiling height too.

Another thought. Just put a coat of latex paint on the down side of the osb instead of vapor barrier. Should work just fine.

When you lay the osb on the sleepers use a continuous bead of construction adhesive to prevent squeeking and creaking.

 

I like the sleeper idea with subfloor glue all the way but I personaly wouldn't use OSB that close to a basement floor. Not saying it wouldn't be perfectly fine I'm just a little old school that way.

 

I can tell you that the national hardwood flooring assoc Does not reccomend osb as a subfloor. This doesnt mean that people dont use it

 

OSB may not be great under hardwood, but under laminate it should be just fine. If you do sleepers, treated lumber is probably the way to go in terms of cost. Untreated studs wiill rot by wicking moisture out of the concrete.

Latex paint is not a vapor barrier--not even close. There are paints that are rated as vapor barriers, but they are pricy. If you're putting down laminate, the foam padding that goes underneath should be a sufficient vapor barrier.

Jason

 

I have seen several laminate floors laid directly on concrete with only the foam underlayment under them. They make a specal underlayment for application directly on concrete. Also get some Dry-Lok paint and paint the floor and wall area where the leak is and it will seal it right up.

if you do want to use the newer composite decking, most are available in thinner boards as well, 3/4 to 5/4

 

http://www.eere.energy.gov/consumer/.../mytopic=11810

 

From the link you posted:

Note the last sentence, plus "acrylic paints are generally better than latex paints". "Latex" paints tend to be cheap, low-solids paints. I know whereof I speak--I'm a self-employed painter by trade.

In addition, I stand by my original statement--latex paint is not even close to being a vapor barrier.

6 mil plastic or the foam padding for laminate would be cheaper and easier than painting a bunch of OSB sheets. Unless he wanted to hire me--then the painting is easier, but not necessarily cheaper.

Jason

 

I posted the link because I learned a few things from it. Not arguing.

 

Not arguing either, just clarifying a few things in my area of expertise. The article was mostly generalities.

Jason

 

If you use laminate flooring, it is essential that you fix that leak before laying it down. Long standing moisture on laminate will ruin the flooring, and it will begin to curl up on you.
Also, you don't want to glue laminate flooring. It is designed to be a floating floor, that expands and contracts with temperature/humidity fluxuations. Point being, it needs to be able to move. You cut the ends, at the walls, approx 3/8 of an inch short so it can expand. The base boards cover the ends.
Another thing. As far as moisture barriers, there are foam underlayments available, made for laminate flooring, that serve both purposes, moisture barrier and softening of the floor. They also tend to pick up any minor imperfections in the levelity of the floor and insulate it giving it a warmer feel and more pleasing step sound. Costco has an installation kit available for laminate flooring that is reasonably priced. It comes with foam underlayment, which is also a moisure barrier, and also has the installation tools you will need. For your basement, I would think that the Costco flooring would be sufficient as well. It's not bad stuff for lighter use areas, and comes with a 25 year warranty. I put it in my kitchen and it seems to be holding up well.
In unwatched areas where moisture might sit for a long time and get under or through the laminate (ie. behind refridge or dishwasher) you're supposed to use silecone calking around the edges. Puddles are supposed to be picked up rather than left to soak. If left for long periods of time, they can soak in and cause damage. That's why I recommend that you fix the leak in the basement before laying laminate, or any other flooring for that matter.

 

you'll want to see what the manufacturer of your exact product recomends.

 

also on the leak, i would check outside and make sure that all rainwater can drain away from the house. as long as the ground is sloped away from the house in all places, the water can't sit long enough to filter down through the soil to leak into the basement. even a small depression in the ground can collect and filter a large amount of water into the soil.

 

With all due respect Jake, in regards to gluing laminates down.
Yes, definately check with the particular manufacturer of the "laminate flooring" you choose to determine the installation procedure. Some manufacturers recommend a 1/4" space at the ends, at the walls, rather than the 3/8" I described in my quote shown above. It varies by mfgr.
But I really DON'T think there is a laminate flooring material that is designed to NOT be a floating floor. I don't believe gluing is what you want to do. Laminates need to expand and contract by design.
Oh well, it doesn't really matter though. Just follow manufacturers direction.