What is Efflorescence?

Have you spotted some white fuzzy stuff on the inside or outside of your basement walls? You probably have an efflorescence problem. Efflorescence is the crystalline deposit that appears white and fuzzy. It is a common problem for masonry block or concrete foundations.

What causes it?

Efflorescence consists of mostly water soluble crystals. When water infiltrates the concrete or block wall, it dissolves minerals as it moves. When the water evaporates from the surface of the wall, the minerals absorbed by the water are left behind forming efflorescence crystals. These crystals can grow with more deposits of minerals.

The more dense the material through which the water has to move through, the more difficult it is for the water to transport and deposit minerals. Porous materials therefore have greater deposits.

There are three conditions that must exist in order for efflorescence to occur:

1. There must be some water soluble salts in the materials used to construct the walls
2. The moisture in the wall must be sufficient to cause the salts to dissolve into solution
3. There must be a path or channel through which the solution can migrate to the surface of the wall where the water can evaporate, leaving deposits of salt to crystalize and form efflorescence.

Efflorescence can only occur when all three of the above conditions are met.

Why you should be concerned with efflorescence

Many people assume that efflorescence is only a visual problem. However, the real problem lies below the surface. The crystals can grow inside the wall. This can result in spalling. Spalling is a term used to describe a situation whereby the surface of the wall peels and flakes off or pops out. As the salt crystals continue to grow and exert pressure on the internal structure of the wall, it will eventually deteriorate and crumble.

Preventing efflorescence

The best way to tackle this problem is to prevent it in the first place. You can do so by ensuring that your wall is waterproof. However, if you do spot some efflorescence on your walls, then you may have a leak. Call in a basement specialist to inspect the wall and determine the source of the leak.

It is important to consider the type of material you use for the construction of your basement walls. If you’re planning to construct or replace a basement wall, ensure that you use a material such as fired clay brick that has chemical additives that prevent sulfates from dissolving into the water.