... sands or polyethylene membranes are spread or covered on its lower surface. It has a good waterproof performance and aging- ... basements, bathrooms and pools of industrial and civil architectures, waterproof, damp-proof, airproof, leakage-proof works of bridges, ... of lapping partIf lapped along longer lines, for single waterproof layer, thelappinglongitudinal/transverse width should not be less than ...