Went through 40 days of rain in this area last summer, leading to a musty smell in the house. I investigated the crawl and was shocked at how awful it was. I opened it up and put in industrial fans to ventilate and, yep, the problem got worse. First step was to fix the gutters and the grade against the foundation. Also discovered I needed a new roof and HVAC but I digress. Once the water entry sources were handled, I began the task of closing the crawl and replacing the existing 4 mil black plastic installed loosely over 10 years ago. I got some bids for this and was stunned. The crawl space is large - approx 3000 sf - but I figured I could take my time and do this myself and save at least 10K. This is not task to be taken lightly. The workspace is damp, dark, and cramped and nasty. Those who are afraid of rodents, snakes, spiders, etc should have someone else handle it. Found a way to wrap piers and walls from another vendor without drilling and anchoring and it is holding up very nicely. Actually got a sample of 12 mil from another vendor and it was vastly inferior to the 12 mil Silverback from Crawlspace repair. Ordered 12 mil for less used portions and 20 mil for the areas to and from the entry to HVAC. This product is thick, heavy and easy to work with. The laying of the vapor barrier was actually the easiest portion of this months long project. The product is virtually impossible to tear, but even the 20 mil can be punctured by sharp rocks underneath. As there is a gravelled french drain in my crawl, I also ordered some of the felt rolls to place beneath the vapor barrier. The tape I ordered was fairly easy to work with but does tend to split and get more difficult to use as you get deeper into the roll. The before/after photos are amazing, but the real difference is in the air quality in the house. Humidity levels in the crawl dropped from the 80s and 90s to less than 60 without dehumidification. Addition of dehumidifier has dropped that number to below 50 with a stable temp of 70. This produces a dewpoint in the crawl well below the temp of the coolest surfaces (HVAC ductwork) therefore condensation is gone. I will follow up on any additional findings. I did my research and the products on this site are outstanding and worth the extra cost. I don't plan on redoing this immense project anytime soon, so I wanted to do it right.

12 mil is good solid material, but it seems to have acquired wrinkles as it was rolled up and the wrinkles hardened into deep, sharp creases that could not be removed. Tried hot air to soften the plastic with little success. As a consequence, it is simply not possible to tape seams securely. Tape can't follow the profile of the creases

Well, I bought it twice in a row. What does that tell ya? Good stuff. Good performance.

BUY THIS AND DO IT YOURSELF.

Challenging crawlspace with wall height ranging from 2 to 3 feet very hard to work in. The product performed flawlessly, and my wife and I were able to install it easily in a couple hours. The foundation tape held the Silverback in place while we maneuvered the roll. The foundation pins went in smoothly and hold the barrier firmly in place. Finished taping the seams and it looks great. I would recommend this system to anyone. We noticed an immediate difference in temperature and humidity once the product was in place. Better than advertised and the assistance we received when ordering was top notch.