Waterproofing is the layout of an Watertight barrier over surfaces of foundations, roofs, walls, and other structural members. The function of the impermeable barrier is to prevent water penetrations. The building surfaces are made water-resistant and sometimes waterproof.

Waterproofing is necessary for the basement, walls, bathrooms, kitchen, balconies, decks, terrace or roofs, green roofs, water tanks, swimming pools, etc.