Laminate Over /\/\/\ WAVY /\/\/\ Concrete??????????????

[infiniteMPG]

We are in process of remodeling our 25 year old Florida home and don't care to have any carpeting, so we're looking at laminate flooring. We have found some wavy spots in the concrete where there variation of up to 1/4" across 3 feet (dips in the concrete slab). We've pretty much picked our flooring with Pergo Prestige with the foam backer.

Have heard some horror stories of laminate on uneven concrete about joint separations and things like that so we'd rather be right the first time. When I was doing the tile in the kitchen, I had bought an

80# bag of Easy Float floor leveler but we found that applying a heavier mortar fixed that without having to level first. Can't do that with laminate.

So two main questions....

1 - How do we use the leveler? Also heard of messy situation and sometimes issues where the leveler didn't stick to the substrate.

2 - Do we need to lay down a moisture barrier before we put down the laminate? The laminate has a thin foam backing, this is a cushion but does it also act as a moisture barrier?

Thanks in advance for your assistance and advice.

[HeyBub]

Won't matter if it doesn't stick. It's meant to be a leveler, not a foundation.

Maybe. Depends on how much moisture comes up through the slab. Tape a 2' square section of plastic (a cut-up garbage bag will work) to the slab for a couple of days. Lift it up to see if there's any condensation on the plastic or if the slab is moist. If all is dry, you probably don't need a vapor barrier.

On the other hand, a vapor barrier can't hurt.

[infiniteMPG]

I guess I have to add another question :

3 - Since the majority of our variation is quite gentle and it's pretty much within 1/8" (there is one dip over several feet that is almost 1/4"), is there a pad or base we can put down prior to the laminate flooring that is "cushion-like" that could compensate for the variation???

[hrhofmann]

Even 1/8 inch will telegraph thru to the surface over time, spend the $ $ and put down leveler. There is a sort of vapor barrier that should be put down under any laminate flooring just to make sure. It is just a thin sheet of plastic that you can overlap if it is not as wide as your floor. Since you live in Florida, the best time to check for moisture is toward the end of the rainy season, in very late summer or early fall. A vapor barrier test now will not be very meaningful. Vapor barrier is inexpensive compared to the Pergo cost, so bite the bullet and put down leveler and then a vapor barrier and then your Pergo.

[infiniteMPG]

We found a product at local Lowe's Tecsun - Premium .25" Laminate Underlayment which is a rather thick foam underlayment that not only cushions the flooring, but acts as a sound barrier and also a moisture barrier and appears that is could take up some slight variations in the flooring. We're going to scope out the whole room and try and assess what the whole picture is.

How hard is it to apply a leveler? We have heard some horror stories about that, too, and would hate to put in a lot of work and end up making the floor worse.

[paulaner]

I just used self leveling compound for the first time and it was easy.

I mixed up a 40 lb bag in a 5 gal bucket and poured it out on my concrete slab floor. I did a total of 4 bags to cover a ~ 11 x 10 area.

I didn't want to buy an expensive float, so I bought a "Concrete Spred" tool at the depot for ~ $20 (link below). It worked out great.

One tip - make sure you have a 1/2 inch drill and mixing tool. My smaller power drill just couldn't handle the load.

[casey]

Greetings infiniteMPG,

Both your questions are answered in the installation instructions. You really need to read the installation instructions, b/4 moving ahead with your project.

[EXT]

Anything soft enough to flatten out over the high spots will also flatten out when someone stands on the low areas causing the flooring to be pressed into the low areas with resulting clicking and possible separation of the pieces. Again you are someone who is trying to find a magic potion that will allow you to do a good job without any effort nor possibly spending any money behind the finished product, it is becoming a common question on this forum. It is what is in the wall or under the floor that makes the finished job last problem free.

[infiniteMPG]

Biting yea old bullet and got an 80# bag of Easy Float that should be enough for that room. Just cleared everything out of the room, cleaned the floor and vacuumed. When we apply it do we just let it flow into the low spots or try to cover the entire floor? Or do we spread it at all like with a wide piece of board or something?????

Kinda new to this.... :O/

[Oren]

If the flooring is/can be glued on concrete (check product), you don't need a leveler (all the time). Some adhesives have vapor barrier qualities, just thicken up in the low spots. Gluing the flooring eliminates the need for foam padding.

Sounds like you mean a "floating" floor with foam under it. That makes sense on a second floor substrate. It reduces sound vibrations, etc.

Put a long level on the floor and rotate to see low spots. Pour the leveler where needed.

[infiniteMPG]

Guess I should read further up the post thread and I would of seen your reply. Sounds like tomorrow I run to the ol' box store and pick up some supplies and then off to the leveler races! :O)

Thanks!!!

[benick]

Check out this flooring..It is called Trafficmaster....Simple to install and needs no floor prep...

My dad put it in his house...A very old Cape with VERY uneven floors...been a few years and still looks great..Available at Homedepot as well as other places...HTH...