Waterproofing is the process of protecting a surface from water. It can be done by applying a liquid waterproofing material to the surface or by constructing a waterproof barrier.
The most common type of liquid waterproofing material is asphalt-based sealant, which is applied to the surface in order to seal any cracks in the surface and prevent water from seeping through.
The most common type of barrier used for waterproofing is a membrane, which has been specifically designed for this purpose. The membrane will usually be installed on top of an existing wall or roof, forming a barrier between it and whatever’s below it.