... ).Convenient maitance with low cost PVC waterproof membrane 1).Durable: If the pvc membranes used on exposed surfaces ... can be more than 20 years.If the pvc membranes used on no-exposed surface, it can ... no pollution to environment 4).Root-resistance: The pvc membranes can be used on planting roofs. 5). ... waterproof and drainage system, pools, dam, irrigation system, light steel roof ect. Item N L W N L ...