Waterproofing a foundation is a process that involves applying a membrane or coating to the walls and floor of a building. This is done to prevent water from infiltrating and causing damage to the structure. The membrane or coating acts as a barrier that stops water from passing through to the interior of the building. There are various materials and techniques available for waterproofing, including liquid-applied membranes, sheet membranes, cementitious coatings, polyurethane coatings, and PVC membranes. The specific type of waterproofing used will depend on factors such as the type of foundation, soil conditions, and the building's intended use. Properly applied waterproofing can prevent issues such as leaks, cracks, and structural damage, ensuring the building's longevity and safety.