The Differences Between Waterproofing and Damp Proofing

Waterproofing and vapor barrier on concrete foundation

Do you know the difference between damp proofing and waterproofing? They’re two terms that are often used interchangeably, but have two distinct meanings. And, the difference between them is incredibly important when it comes to properly protecting a building’s foundation. Here’s an overview of both waterproofing, and damp proofing, as well as an explanation of why it’s important to know the difference.


The process of waterproofing a concrete foundation provides a continuous barrier to water penetration. By treating the surface with either tar, or an elastomeric rubber coating, that barrier is created and it’s able to withstand hydrostatic pressures. These materials can either be sprayed onto the surface, or applied by hand. The main concern when deciding whether waterproofing is needed, is how often the structure will need to deal with standing water. The depth of the foundation wall, the use of the interior space, and the surrounding climate, will all be factors in this determination. In general, however, if there is any question over whether waterproofing is needed, it most often is.

Damp proofing

When damp proofing a concrete surface, a coating is applied in a similar fashion as when you’re waterproofing. This coating material is typically asphalt based and forms a membrane. The primary difference between waterproofing and damp proofing is that this membrane isn’t expected to prevent penetration by standing water when hydrostatic pressure is present. In other words, damp proofing is intended to keep small amounts of moisture from damaging the surface, but won’t completely seal the surface the way waterproofing does. Damp proofing is also unable to fill large cracks or holes present in the concrete. If proper surface drainage is possible, and drains are installed correctly, damp proofing can still be a viable solution in many applications, however, it’s rarely used in modern residential construction.

Whether your next project requires damp proofing, or waterproofing, come see us at Maxwell Supply in Tulsa for help finding all the products the job requires. We carry a variety of waterproofing products, including ThoroSeal, one of the most trusted brands on the market. Give us a call at 918-836-8606 or stop in and see us today.