I have used their product a couple times and those times the slab was over the limit of 3lbs and I used six mil plastic under it. But was reading their installation giudelines (preparing for another tomorrow) and it says to test and make sure the slab MVE is not over 3lbs. Then again it says it is 75% better than any other underlayment out there and any other "film" is not required.

This makes absolutely no sense to me. If it were so great one would be able to go over a slab running 10lbs. But they have another that has the plastic flap and pre-adhesive on it. That one seems better suited for a job without another film.

Me, I just don't trust any of these underlayments to perform above 5lbs. Anyone use this on slabs without another film like 6 mil? Guess I better run out and buy a roll of 6 mil. I sleep better.

http://www.floormuffler.com/floormuffle ... ffler.html

http://www.floormuffler.com/floormuffle ... tions.html

That's weird. I would sure throw the 6 mil. down.

I haven't used floor muffler. I remember when Gary was posting...He was a big fan of that stuff. We had a few small battles between Quiet Walk and Muffler, hehe.

Yea, I went and bought a 1,000 ft roll. Heck, @ 6.4 cents a ft it's cheap insurance for me. I has a reputation to protect ya know. All these underlayment manufacturers won't tell you they only work up to 5lbs using a CaCl test. After that it's cup city and your on the hook even if you did a CaCl test and it was within they're requirements at the get go. All of us who work on concrete regularly know....it will always changes.

DIY'ers take note.

Absolutely. Not to mention some of these underlayments...their "vapor barrier" is like plastic rice paper or TP