waterproof belt 1Gray putty-like gel, 2weather resistant, anti-aging, 3 anti-leaking, erosion resistant, PN (BW) waterstop strip is a new type of waterproof building material with self-adhesive property synthesized by polymer, inorganic water-swelling material, rubber and additives. It could absorb water and expand volume, compact the gaps between new and old concrete, to form watertight ...