The CleanSpace vapor barrier is a poly string reinforced liner with an antimicrobial called UltraFresh built-in. CleanSpace is durable enough for service persons to crawl on it and maintain plumbing or HVAC equipment, without damaging the liner. When CleanSpace is installed, all seams are overlapped and sealed, it is fastened to the crawl space walls 6 inches above outside grade, and wrapped around piers to completely seal your crawl space off from the earth's moisture.