Our black waterproof glue contains dibutyl ester and sodium chloride. It can be waterproof and mold-proof, that is, it can penetrate the cracked area and then form a waterproof layer on the surface. Its usage method is very simple: Clean the construction surface to ensure it is free of moisture. Apply this product directly to the construction area with a brush. Wait for 24 hours to dry. During this period, do not come into contact with water. Once a waterproof layer is formed, water will not seep in. And it can be waterproof.