See our review of the Guardian 12 Mil Reinforced Vapor Barrier.

This is the tape we use to attach the sections of vapor barrier and around vertical obstructions for a continuous application.

Even after ordering extra rolls of this tape I still ran out but luckily I had extra "two way" and substituted to get the job done! You won't mind having left overs of these tapes, there made so well and will have many other useful applications around the home or workshop.

The Silverback vapor barrier seems to be very durable and easy to work with. I did a lot of leveling of the gravel in my crawlspace which made everything relatively square. I can see how an irregular surface may lead to a more difficult installation.

I was considering 20 mil vapor barrier on the recommendation of a spray-foam contractor, but after reading the specs and knowing that I was installing on plain dirt and won't be storing anything on top of the barrier I decided to go with the 12 mil. The 12 mil silverback is really durable, but easy to cut with a razor knife and easy to work with in a confined space as long as you cut it to size and fold it correctly prior to taking it into the crawl space with you. I cut the pieces to size (piecing together where needed with the tape, since the roll was 13'4" and my crawl space is 17x21. I cut it 1 foot longer and wider than the crawlspace dimension to allow it to go up the foundation wall by 6" all the way around. (The spray foam insulation will seal the edges to the foundation block). When folding it, I chose to fold it from the outside edge towards the middle - with the two long edges meeting in the middle. Then I repeated the process and folded the resulting long, narrow piece in about 3-foot squares. Using this method allows you to position the folded barrier in the center of one end of the crawlspace, unfold it length-wise, then kneel in the middle and fold each side out to the sides. The whole process was pleasantly much simpler than I anticipated, with the exception of getting covered in spider webs.

 

I sealed my partial crawl space with this 12 mil liner along with the felt underlayment, foundation seal tape and seam tape. Delivery was prompt and the products easy to work with. No pvc smell at all. I should have done this years ago! I had extra so I added a second layer where I store tote bins. The seal is so tight that the liner puffed up due to air infiltration.