I've read pro's and con's on the Lowes product. Mainly an odor issue...like tar or something.

I helped my brother encase the whole outside of his basement with a thick stick on membrane. Man was that stuff sticky.

I did find this while surfing. Price is bit higher, but you get allot of it.

http://www.raamaudio.com/products/RAAMmat-BXT-II.html

Thanks for the link, it also looks like a good place to start.