VaporFlex under slab vapor barrier prevents moisture and water vapor from infiltrating through concrete slabs and foundations. The barrier is durable, with high puncture resistance and low permeability rates. It's manufactured from a blend of virgin polyolefin resins and performance additives to exceed standards for a Class A vapor barrier. The material is available in 15 and 10 mil thicknesses in easy-to-use rolls of 12x150 or 15x196 feet. The Layfield Group. 800-885-8825.