Saw a guy in Phoenix use a different underlayment trick for concrete slabs

I was helping a friend on a big commercial job in Phoenix last month, and the lead installer showed me something new. He was putting down a 6mm vapor barrier over the slab, but instead of just taping the seams, he used a specific adhesive called 'SeamLock 200' and rolled it with a 100-pound roller. He said it stops moisture better than regular tape, especially in dry climates. Has anyone else tried a method like this for concrete subfloors?

3 comments

3 Comments

spencer_gonzalez121d agoOG Member

SeamLock 200 seems like overkill for a basic vapor barrier.

the_alex21d ago

Yeah, that SeamLock stuff is legit. We used it on a data center slab last year where the specs were crazy strict. It's a pain to roll out, but you get a way better bond than tape. In a place like Phoenix, that extra step makes sense to me.

the_jessica21d ago

My cousin in Tucson had a slab lift two inches after a monsoon season. The contractor blamed a failed barrier seam. I get why someone would want that extra seal now.