To waterproof basement walls, select the type of sealant appropriate for the walls. There are four basic types of sealant for basement walls: concrete coatings, silicate-based sealant, waterproof acrylic paint, and plastic sheets and panels. Apply the concrete coatings to clean basement walls with natural fiber bristled brushes. The waterproof acrylic paint and the silicate-based sealant can be applied to clean walls with brushes, paint rolls or spray bottles. Plastic sheets and panels can be secured with adhesive and screws.
Concrete waterproof coatings stick permanently to concrete and masonry walls once they are applied. The concrete coating goes on thick and does not properly or lastingly adhere to walls that have previously been painted.
The silicate-based sealant is a chemical solution that seeps into the surface of the basement brick, concrete or masonry wall to create a hard waterproof surface. Because the basement walls absorb the sealant, it does not flake or peel off, and it can be painted over.
Acrylic paint is similar to other types of paint but is a little thicker. When it cures and dries, the acrylic paint becomes hard and waterproof.
Plastic sheets and panels do not create a waterproof seal on the basement walls, but they can be used to repel moisture and condensation that accumulate on the wall. This is an ideal form of waterproofing the basement walls if they have already been painted and sealant cannot be applied to them.