Damp Proofing: Does Basement Waterproofing With Tar Work?

Have you ever seen the outer side of basement foundation walls coated in tar? This method of basement waterproofing has been around for a very long time. In fact, it is still used today in some locations for new construction methods. Some highly effective solutions, like exterior waterproofing installation, can resemble a tar coating on your foundation walls. What has actually been applied, however, is a non permeable membrane that far supersedes the performance of a tar coating.

Our professional waterproofing experts at BARRIER Waterproofing Systems recommend some highly effective solutions over waterproofing with tar for your foundation. This is because of the numerous downsides that this method brings for homeowners trying to protect their basement from moisture. Listed below are some of the disadvantages of basic tar waterproofing you might want to know about:

Installation Times Can Vary

In warmer temperature conditions, the installation process for a tar coating can move along pretty quickly. In colder weather, however, the process can take as long as one week to be completed! The colder it is, the longer the time frame that is needed, and this situation can end up weighing rather heavy on your pocketbook.

Toxic Fumes Emitted From The Tar

Tar is full of harmful VOCs (volatile organic compounds) and PAHs (polycyclic aromatic hydrocarbons), otherwise known as carcinogens. The toxic fumes released during application can be very offensive to most people and can also linger for several days to a week after installation is complete! In some cases, the smell has been strong enough to affect any neighbors living close enough nearby.

Rather Limited Performance

Tar is most often used in an application referred to as Damp proofing. This is because tar proves moderately effective against dampness, although tar simply does not hold up when it comes to intruding moisture. Water wears tar away, reducing its effectiveness and causing it to crack and break down over time. In contrast, high-quality waterproofing materials can last for decades!

Lack the Flexibility Needed to Withstand Cracking

There is no way to prevent your home’s foundation from shifting entirely. It is inevitable that the soil around your home will both expand and contract when moisture enters in and evaporates out. This causes pressure to push inward on the foundation walls and then draw them outward as the soil dries out. A tar coating is made of materials that lack the flexibility needed to remain intact while moving with foundation shifting.

As a result, the tar application will develop more and more cracks as it ages, eventually breaking down. Moisture will soon find its way through the cracks in no time, rendering the tar application entirely ineffective.


Damp proofing is still a common enough practice that some builders apply it to new construction every day. Some homeowners purchase a home previously equipped with a tar coating, but they are not at a loss of being stuck with it. Professional waterproofers, like our team here at BARRIER Waterproofing Systems, can ensure your home is taken care of. We can help remove the initial tar application and install a highly efficient and superior quality waterproofing membrane in its place. 

For more information about how damp proofing stacks up against professional waterproofing solutions, give us a call at (615) 257-1060 | (931) 536-1168. You can schedule a FREE evaluation of your home and visit our website to learn more about the benefits we can offer your quality of life.