What’s The Difference Between Waterproofing And Damp Proofing?
Damp proofing has been a standard practice when building new basements and foundations for decades now. The thing about concrete is that it’s porous, so it’s fully able to absorb water from the environment around it, and the thing about dirt is that (outside of deserts) it’s full of moisture. This means that the moisture in the dirt can condensate on the cool stone walls, infiltrate it, and then slowly deal damage to the foundation and its contents.
To stop this process, the International Residential Code added rules to apply a damp-proof layer to the outside of every concrete wall and slab up to where the soil ends. There’s also a rule about waterproofing basements, but it’s only required for construction in places where a basement flood is a likely possibility.
The damp-proof layer is usually nothing more than a spray-on paint or chemical which is at least waterproof enough to keep condensed water from getting into the concrete. However, the layer isn’t particularly durable, and when the concrete cracks, so does it. This means that it can’t stop rainwater or groundwater under hydrostatic pressure from worming its way in through the cracks.
By contrast, an exterior waterproofing system involves a series of drains buried just below the foundation base which takes in water and moves it safely away from the building, and it may also include a durable rubberized membrane on the outside of the walls which renders it completely waterproof, cracks and all. Of course, all this added effectiveness comes with an added price, which is why it only comes recommended for homes which would really put the coating to the test.
Damp proofing and waterproofing are two entirely different processes and should never be confused with one another. A damp-proof coating isn’t enough for a house built in an area with a high water table, and a waterproof treatment is overkill for a house built on the side of a hill in a drought zone. When you’re looking at waterproofing options, make sure you ask a company with a strong reputation like AA Action Waterproofing, a company that will tell you honestly what your home needs and what it can do without.