Waterproofing Paints Don't Always Work

Waterproofing paints have been used as a common solution to prevent water penetration through walls or substrates. However, their effectiveness can be limited in situations where they are applied to the negative side of the wall or substrate. In this article, we will explore why waterproofing paints don't work in such scenarios.

First, let's understand what we mean by the negative side of a wall or substrate. The positive side is the surface of the wall or substrate that faces the exterior or the source of water, whereas the negative side is the opposite surface that faces the interior of the building. When water pressure comes from the positive side, it is relatively easy to prevent it from penetrating the wall or substrate by applying a waterproofing paint or membrane. The coating acts as a barrier, preventing water from seeping through. The pressure pushes the coating against the substrate, which buttresses it.

However, when water pressure comes from the negative side, the situation is different. The water pressure can build up on the negative side and push against the waterproofing paint or membrane, causing it to delaminate or peel off. Nothing is behind it to buttress it. When this happens, water can seep through the cracks or gaps in the coating and penetrate the wall or substrate. This is known as a negative side water pressure problem.

The negative side water pressure problem is common in below-grade structures, such as basements or foundations, where water can accumulate on the outside of the wall or substrate and exert pressure on the negative side. This pressure can be caused by a high water table, heavy rain, or poor drainage. This is a very damaging force.

Another issue with waterproofing paints is that they are typically not designed to withstand hydrostatic pressure. Hydrostatic pressure is the pressure exerted by water when it is at rest, such as when it accumulates behind a wall or substrate. When hydrostatic pressure builds up, it can cause cracks, fissures, or fractures in the wall or substrate, which can allow water to penetrate.

So, what is the solution to the negative side water pressure problem? One solution is to use a waterproofing system that is designed to withstand negative side water pressure. Keystone Basement Systems can help you with this. These systems typically involve installing a membrane and system on the negative side of the wall or substrate. This membrane and system is designed to withstand the pressure exerted by the water and prevent it from penetrating the wall or substrate.

Another solution is to address the source of the water and prevent it from accumulating on the outside of the wall or substrate. This can involve installing drainage systems, improving the grading around the structure, or waterproofing the exterior of the wall or substrate.

In conclusion, although not recommended, waterproofing paints can be an effective solution for preventing water penetration through walls or substrates when the water pressure comes from the positive side. However, in situations where the water pressure comes from the negative side, waterproofing paints can be ineffective if applied to the negative side to combat it and may even exacerbate the problem. It is essential to address the source of the water and use a waterproofing system that is designed to withstand negative side water pressure.