Damp Proofing Vs Waterproofing: Difference Between Damp Proofing And Waterproofing

If you are the proud owner of a home or any building, there’s a good chance that you have found yourself debating damp proofing Vs waterproofing. You might not exactly understand either on a technical level, but you probably know that they are necessary without a doubt to ensure the integrity and longevity of your home or building. All that aside, this probably leaves you wondering what is the difference between damp proofing and waterproofing? Well, that is exactly what you are going to learn below and more.

The first thing that you need to understand is that most experts will tell you right away there is a distinct difference between waterproofing and damp proofing. In fact, it is damp proofing that is intended to keep out soil moisture, while waterproofing is designed to specifically keep out both moisture and liquid water. There is no denying that the two are somewhat similar and it would be more than easy to understand why anyone debating damp proofing Vs waterproofing would consider them the same. As you can see, this is, however, not the case.

Key Difference Between Damp Proofing And Waterproofing

To the uninformed individual, damp proofing and waterproofing might seem like the same thing. In fact, there are several individuals that confuse the two every day. While this might not seem like a huge mistake, it is one that will not only be time-consuming, but it could be more than costly in the long-term. The real key differences between the two are the physical differences between the construction materials that are used in the processes. Not only this, but the applied thickness and the conditions of the application also vary from situation to situation.

Understanding Damp Proofing

Damp proofing is a process that works where tar or unmodified asphalt-based materials are hand-applied or sprayed to the outer surface of a wall. The main purpose of this entire process is to stop the wicking or transference of ground moisture through the concrete. Now, the thickness of this coating can vary depending on the severity of the situation and region. Most areas will utilize a coating that is right around ten mils thick.

One good thing about this process is that it is fairly basic. Not only this, but it is more than a viable solution in several situations where moisture is a major problem. All that aside, here is where the real confusion comes in. Damp proofing is not a process that is intended to keep all the water and moisture out. No, it’s a process that was specifically designed to halt the moisture. Therefore, it does exactly this by blocking the concrete pillars to slow water penetration.

Another major misconception with damp proofing is that it does not seal larger cracks, big holes, or any other damaged surface. If you combine damp proofing with an adequate and properly installed drainage system, you will be able to provide your home or building with long-lasting moisture protection.

Understanding Waterproofing

Waterproofing, on the other hand, is a process that was specifically designed to properly stop the infiltration of water through concrete structures. The materials that are utilized in this process do have the ability to bridge those bigger cracks and gaps in foundations, whereas damp proofing materials do not. This is where a lot of confusion comes in. Not only this, but the materials that are used for waterproofing are generally more versatile. This is because they are flexible and elastic in nature. Check out this article I wrote on the most common materials used when damp or waterproofing.

Another major difference between the two processes is the thickness of the materials that are used. You learned above that in most damp proofing situations contractors will use 10 mil materials. This is not the case with waterproofing. During this process, contractors will use materials that are at least forty mils. This is because these materials need the ability to withstand hydrostatic pressure as well as moisture. Some of the more popular choices for this process are crystallization products, clay-based products, rubberized-asphalt coatings, urethane coatings, butyl rubber sheeting, and other rubber-based coatings.

At the end of the day, waterproofing materials must really be able to accomplish three different things. They must stop water vapor, stop water under hydrostatic pressure, and span a crack. Waterproofing is essential in all homes and buildings, but it will be even more important in those areas where there are high water tables and significant rain.

Things To Consider Before Waterproofing Or Damp Proofing

It’s safe to say, there’s no real estate owner that wants to deal with water damage. A wet basement or crawl space is just asking for trouble. This is not to mention the fact that once the water has penetrated the home it is harder to eliminate. Therefore, it’s best to avoid that dreaded damp basement in the first place. Unfortunately, this might not always be possible, especially if you are buying a used home or building. However, if you become knowledgeable in this area, there are some things that you can do to prevent the dampness and water build up in the first place.

Researching Waterproofing Methods

The very first thing that you need to know and understand is that there are a number of waterproofing techniques out there, but there are three main ones that are usually utilized. This would be interior sealants, drainage, and exterior waterproofing. You also must investigate the cause of the potential water damage in the first place. This will only help you better determine which method is more suitable for you and your real estate property. In most cases, you can simply reach out to a local waterproofing company, explain your situation to them, and they will probably give you the advice and information that you are seeking.

Always Avoid Stagnant Water

Any time you have water in the home you must act immediately. You do not want to sit around and let the water evaporate because in most cases this will lead to serious issues in the near future. Stagnant water not only looks and smells bad, but it can build bacteria and pose tons of health problems. Therefore, you want to act immediately. Experts recommend that any time water seeps through the walls, floors, or ceilings, you shouldn’t hesitate to remove that water within at least 24 to 48 hours of the incident. This will prevent any fungal or bacteria growth in the home. You should always remember that mold and fungi can be tricky, as they can thrive in these moist conditions. Nevertheless, just because you don’t see or smell them it doesn’t mean that they aren’t there thriving.

Damp-Proofing An Existing Foundation

Since damp proofing doesn’t create a watertight seal, it is not recommended for new applications. What this basically means is the process is not suitable for first-time applications. The damp proofing process calls for the use of an asphalt- or tar-based mixture, which is to be applied to the exterior surface of the foundation. Most of these products are black in color, so they are not suitable for concrete and block foundations that are visible from the curb. However, some people do not mind the black coloring if it prevents moisture from penetrating the wall, basement, sidewalk, or other structures.

Before you damp proof your basement, retainer wall, or crawlspace, you need to know the building codes in the city or county you reside in. The damp proof coating must be installed to meet your local building codes.

Damp proofing installation generally focuses on the exterior surface. To achieve the maximum results, it’s best to hire a professional to do the job unless you are prepared to do a lot of digging and pressure-washing.

  • Step 1 – The first step of the process involves clearing the area around the foundation. To do this you will need to dig the dirt and rock out around the foundation. You will need to leave a good distance from the dirt and foundation for working space.
  • Step 2 – The second step involves cleaning the surface of the foundation. To thoroughly clean the surface, you will need to utilize a heavy-duty pressure washer. If you do not have one of these machines, you can rent one from your local big-box store. Utilize the high-pressure water to remove dirt and debris from the surface before moving on to the next step.
  • Step 3 – Wait between 24 and 48 hours for the concrete to completely dry before installing the damp proofing product.
  • Step 4 – Once the surface of the foundation is completely dry, you will need to repair any chips, splits, holes, or cracks before installing the damp proof coating.
  • Final Step – Follow the instructions on the back of the product to complete the installation.

Disadvantages Of Damp Proofing Products

Where damp proofing products have advantages; they also have some disadvantages. The biggest disadvantage of these products is a short lifespan. Regardless of the application or installation, these products generally fail after a few years, two years in most cases.

Another disadvantage of these products is they are extremely difficult to install on existing foundations. Since damp proofing products do not create a watertight seal, they are not recommended for as highly as waterproofing products. This is especially true for building foundations, such as basements and crawlspaces. They are also not recommended for people who desire a clean-looking, dry surface.

Damp proofing products set and cure quickly. The outcome is generally a brittle, rigid surface. When utilized on a new concrete application, the product will crack as the concrete expands with alternating moisture and temperature levels.

Professional damp proofing is most often more expensive than professional waterproofing. This is due to the difficulty of installation, as it requires heavy equipment to complete the process. It can take several days to fully complete a professional damp proofing job. On the other hand, professional waterproofing can be completed in a single day because it can be done from the interior of the structure.


When it is all said and done, you can clearly see that waterproofing and damp proofing are more than different practices. Yes, they are similar, and it is also easy to understand why many people confuse the two. All that aside, it would be hard for any home or building to withstand the test of time without undergoing either practice. Not only is each practice essential to ensuring the well-being of your real estate property, but it might be required by building code. In fact, there is more than a 90 percent chance that you live in an area where the law requires your home or building to be damp proofed and waterproofed during the building process.

Related Questions

Does Damp Proofing Require Building Regulations?

Anyone that is building a home or living in a building with damp or water problems is probably wondering this very question. If you have read this far into the article, then you already know that there are building regulations involved with both the waterproofing and damp proofing processes. However, this does not mean that the regulations aren’t varied from city to city or state to state. According to the International Residential Code (IRC) Section 406, any concrete wall that retains earth and encloses interior spaces and floors below grade must be damp proofed. Not only must it be damp proofed, but it must be done so from the top of the footing all the way down to the finished grade.

Along with this, the IRC provides a list of accepted materials that can legally be utilized for the process. Amongst some of these materials, you will find bituminous coating and acrylic-modified cement. As far as waterproofing goes, it is only required by the IRC in areas where a high water table or other severe soil-water conditions are known to exist.

Is Damp Proofing Necessary?

Not only is it necessary for ensuring the well-being of your home or building, but it is essential to ensuring the well-being of your family. You would be surprised at the plethora of health problems that come along with stagnated water. This is not to mention all the potential mold problems. Dampness and water are viable living conditions that mold spores will thrive in. If they are abundant in your home, then it won’t be long before spores develop and spread. With that being said, there are certain situations where waterproofing will work better than damp proofing. A general rule of thumb is if the dampness is in the basement or earth retaining walls then a full waterproofing system will be your best option. If the water or dampness is above ground level, then you’ll probably need to opt for a damp proofing system to rectify the problem.

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