Damp proofing and waterproofing may sound like the same thing, but there is a distinct difference between them. A few of the key differences include the physical properties of the construction materials used, the applied thickness, and the conditions of the application service. The intention of damp proofing is just to keep the soil moisture out while waterproofing is done to keep both the moisture and water out.
Damp proofing is a process where tar or unmodified asphalt-based coating is hand-applied or sprayed on the outer surface of the walls. Its main purpose is to stop the wicking or transference of ground moisture through the concrete. The thickness of the coating will usually be less than ten mils. Damp proofing is a very basic and acceptable treatment in various moisture situations. It is not intended to keep all the water and moisture out, but rather just retard the moisture infiltration by blocking the concrete capillaries to slow water penetration.
Damp proofing does not seal larger cracks, big bug holes, form tie holes, surface protrusions or other large damaged surfaces. With adequate surface drainage and properly installed foundation drains, damp proofing can provide adequate and lasting protection.
Waterproofing is designed to properly stop the infiltration of water through concrete structures. The materials used for waterproofing have the ability to bridge cracks that may develop over time as they are flexible and elastic in nature. The thickness of the coating applied, often in excess of forty mils, comes into play as well. These materials can often withstand hydrostatic pressure as well. The following are the materials usually used in waterproofing applications.
- Crystallization products
- Clay-based products
- Rubberized-asphalt coatings
- Urethane coatings
- Butyl rubber sheeting
- Rubber based coatings
A waterproofing must essentially be able to do three things. Stop water vapor, stop water under hydrostatic pressure, and span a crack in the treated concrete. Waterproofing is important in areas where there are high water tables and significant rain.
A few of the variables that you have to consider before deciding on waterproofing or damp proofing are the soil conditions, drainage conditions, water table level, moisture tolerable degree, and sub-grade depth. Waterproofing costs more, compared to damp proofing. It is always better to check with a professional whether you need waterproofing or damp proofing. If waterproofing is required to prevent leaks, and moisture buildup, like basement leaks or basement moisture, and to prevent damage to the foundation of your home, then it is better to go with it, rather than inviting health issues and incurring possible home repair expenses in the future.