Previously, this crawl space had a 6-mil lightweight vapor barrier that was torn and even missing in places. We installed the CleanSpace Encapsulation System. The CleanSpace vapor barrier is a heavy-duty 20-mil liner that is perfect for crawl spaces that have service persons working on equipment, plumbing, or electrical, or for storage. It resists rips and tears, and is fastened to the walls and wrapped around piers sealing the earth off from the home.