Interlaced 90 MIL LINER crawl space and basement vapor barriers turn the worst crawl spaces into works of art. No other liner on the market can compete with its ease of installation, beauty, and performance. Whether installed over drainage matting or by itself, 90 MIL LINER adds to crawl space comfort for both the installer and the homeowner. Great for basement wall applications as well! May be used to cover foundation walls as a component of an interior waterproofing system. Interlaced 90 MIL LINER is composed of three layers; white cross-woven polyethylene vapor barrier expanded poly foam core and metallicized reflective foil.