5 Foundation Waterproofing Methods

basement with white walls and concrete floor

It is essential to apply foundation waterproofing to prevent mold damage and protect the area in the case of a flood. Understanding how to waterproof a foundation will help you to determine which option is best for you.

Rubber Membrane

Rubber membranes are ideal for waterproofing a basement as they are not only effective, but also eco-friendly because they contain no toxic substances and do not cause damage to surrounding property. They can be applied to both the internal and external surfaces of the foundation in order to prevent the ingress of not only water, but also air and insects.

Rubber is a convenient method as it can be applied by spraying or painting it onto the surface and it requires no priming. The result will be sufficiently flexible to maintain its ability to move.


bag of bentonite clay

This clay-like substance is a good material to use as foundation waterproofing due to its ability to absorb water until it expands to its full capacity. It can take-in a significant amount of water and create a permanent seal once it has had its fill.

The panels which are formed from the material can be hammered or stuck into place. They can be combined with butyl rubber to create a sheeting that is effective against water ingress. It is non-toxic, so it is safe to use and will not cause damage to surrounding property. It’s also quite easy to apply.


Cement products are among the most popular foundation waterproofing methods because they are relatively cheap and readily available. Cement is easy to mix and can be applied with a brush. An acrylic solution can be added to the cement to make it bond better with the surface and create a more resilient coating. On the other hand, cement is rigid and unyielding; therefore, it can crack when it is subjected to small movements that are normal for buildings.


flooding basement

Rubberized sheets of asphalt membrane can be used as foundation waterproofing. They are made more convenient by being manufactured in a self-adhesive manner so that they can be fixed into place after removing a protective film.

This method requires skill. Once the asphalt is stuck to the surface, that is where it stays. It needs to be done correctly the first time. Wrinkles and air pockets can only be rectified by cutting the defective section of the membrane out and smoothing it. Holes must be covered over with an additional piece of membrane. It cannot be lifted and replaced.


Liquid tar can be applied to the surface in order to create a waterproof barrier. It is sufficiently thick and sticky, allowing it to be added to sheets of felt to build layers so that water cannot pass through.