... 0mm 2).Convenient maitance with low cost PVC waterproof membrane 1).Durable: If the pvc membranes used on exposed surfaces,the ... can reach 50 years. 2).Excellent resistance to ageing and weathering 3)Fine UV-resitance, no pollution to environment ... for roof construction, subway, bridges, channel tunnel, planted roof, waterproof and drainage system, pools, dam, irrigation system, light steel roof ...