the tape sticks to concrete with no problems

I purchased this product because the encapsulation installer (AFS) I hired was planning to use "nail & washer" to attach liner to foundation walls. While I am not a structural engineer, common sense tells me that if you shoot a nail into a cinder block, there is a potential to crack the block. To ensure they would do it the right way, I put it in the contract that they would use pins. While the installer is to bring his own pins, I decided to purchase a few bags to ensure the installer has enough pins to do the job properly (and if they didn't, I will sell them the bags). As a note, AFS is a reputable company; but as a caution, installers will try to get away with doing things the easy and the wrong way. Make sure you watch all the videos on crawlspacerepair.com to understand the work required to encapsulate a crawlspace.

Highly recommend the 20 mil for the floor of your crawl space. If you can afford it, use it on the walls as well. It is heavy duty and really makes a difference. Strongly recommend making accurate measurements and cutting it in a place where you can stretch it out as it comes folded onto itself.

I was a bit concerned when I received the shipment of the roll that although it was 80lbs it didn't look quite wide enough to do the job. However, it's amazing just how tight they can roll that stuff as it was not only adequate but quite thick. In fact, we had to devise some creative ways of applying for long rolls. Very nice product, no smell at all, appears it will last for many years.

Went up easy and seals crawlspace perfectly