View Full Version : Vapor Barrier Controversy

08-19-2006, 08:01 AM
I'll be laying down my Du Pont Laminate flooring in a couple weeks when I'm finished painting etc.
It's going to be installed on my concrete slab.

I'm hearing two different opinions about which vapor barrier to use.
I've already purchased some 6 mil plastic sheeting which an experienced big box told me to buy when I bought the laminate.

I happened to run into the store manager of the other big box guy--during discussion he told me it would be a mistake to not seal the slab with
a liquid sealer instead. He isnt the first to tell me this.

Manufacturer Du Pont however is specific about installing plastic sheeting in instructions with no mention of sealer.

Whats up?

08-19-2006, 10:05 AM
I am not familiar enough with the performance of concrete sealers to say that any of them are "good enough" to protect laminate flooring. But if the flooring manufacturer specs a vapor barrier, you just need to do it because it will otherwise void your warranty. Moisture issues come up all the time which affect laminates, and if you have a problem, they will take one look and say "No vapor barrier...sayonara kemosabe"!

08-19-2006, 12:53 PM
Follow the manufacturer's instructions if you want a warranty.

If you haven't checked you slab for level...do it before you start the installation. Laminates need a very level surface, or you'll have failures. The manufacturer probably also sells either a foam or bubble wrap type underlayment. The extra cushion provided by this type of underlayment makes the floor more comfortable and can increase the life. Many of these can be used instead of the plastic. Just make sure to seal the seams with the prescribed tape to create the vapor barrier seal.

08-19-2006, 03:53 PM
Jimbo-thats the best way to go-I agree.

Jadnashua-funny you should mention the tape.
My original question for this guy was what kind of tape to use, as a matter of fact.
This big box store manager told me the tape was a waste of time-and would do nothing-dont bother. right?

Instincts told me he's nuts. That one reason I started this thread.

BTW My slab is level-I checked before buying the laminate. It also has the foam backing so it's all good in that regard...

08-20-2006, 06:26 PM
I had a choice to buy the manufacturers foam for about 2x as much, or the rolls from lumber liquidators for $12/100 ft.

I don't really care about the warranty. Saving the $100 was the direction I went, since the foam is basically the same as the mfrs.

I'm using the stuff from costco, which is rebranded quick-step. I also bought my transitions, mouldings, and quarter round from LL. Their beech is very close to the costco maple. (close enough), and a 7.5' stick at LL is $4.80 versus $7/$8 elsewhere.

I wasn't impressed with LL's laminate though.

08-21-2006, 06:59 AM
Well, I still cannot seem to get answer for someone experienced about which tape to use with 6 mil vapor barrier over concrete.

Could have sworn I read where plastic shipping tape is OK. Duct tape would seem logical, although it is a little thick?

08-21-2006, 08:23 AM
Don't use duct tape - the adhesive will dry out and it isn't that waterproof anyways. I know when I installed some enginerred wood flooring, they specified a specific 3M product (looked like packing tape, but had a different adhesive). You could probably use the tape specified for one of the housewraps like Tyvek. That is designed to hold up for extended times. The flooring I used is make by Kahrs, you could read their installation instructions, but I think they've changed it and now there is a taped strip on the underlayment itself, they may no longer use a separate roll.

08-21-2006, 12:20 PM
Gotcha. I found it...it's a dupont product that has a permanent acrylic adhesive..

Now I need to find it here locally.