Waterproofing in buildings is the formation of an impervious barrier over surfaces of foundations, roofs, walls and other structural members of building to prevent water penetrations through these surfaces. The building surfaces are made water-resistant and sometimes waterproof.

Commonly used materials for waterproofing in building is cementitious material, bituminous material, liquid waterproofing membrane and polyurethane liquid membrane etc.

Waterproofing in buildings and structures are generally required for basement of structure, walls, bathrooms and kitchen, balconies, decks, terrace or roofs, green roofs, water tanks and swimming pools etc.