I wouldn't use this tape on oxidized concrete as the dust wont allow it to seal properly. I would use spray foam if I did it again

1) GOOD: This is not like roofing "42" , and shouldn't be. 42 has an organic fiber base which will decay if continuously wet, as underneath a vapor barrier. This synthetic product is just what is needed as a vapor barrier underlayment. 2) OK: I got this to protect my vapor barrier from sharp-edged gravel which was already covering my crawlspace floor. As such, this product is OK, but not as thick as I expected. It is like an extra-thick landscape fabric.

Product is durable & easy to work with in a crawl space, it is packaged tight.

The product is excellent quality and simple to use.

This will sound like a paid review, but is not. I have no business relationship with Crawl Space Repair, and did not know of them before searching on the internet for materials and instructions for sealing my crawl space. The shipping and materials exceeded my expectations. The materials are as good as claimed. The Silverback poly is tough and has no funny smell like other polys from reclaimed plastic. The 550 felt does a good job of adding protection over rocky soil, and the plastic tape sticks like glue yet is flexible. I ordered on a Monday and received my order that Thursday, for free shipping (12 mil Silverback). 12 mil was plenty thick and I would not have wanted a heavier plastic because it gets hard to handle around corners, of which I had many - crawlspace under geodesic dome. Once the felt was down, I walked in my socks to keep things clean, and walking over the poly did not puncture it anywhere. The job was not as complicated or difficult as I thought it would be and I'm very glad I did it.