Tim Carter
Q: Tim, I have a problem with my brick home. I live in Houston, Texas, and have a sprinkler system for my lawn. The water sometimes gets sprayed on the brick exterior and white stains appear. I’ve tried scrubbing with water and a water/acid mix. Nothing is working. What’s going on and how do I stop it? -
A: This problem is quite common. I even have the issue in my own garage in the winter months. The problem is efflorescence.
Dissolved minerals are present in just about all drinking water. Some cities, towns and wells have more than others. You might see white water stains on your drinking glasses or a dark countertop, if a water drop dries.
The minerals can also be present in the mortar in between the brick. Even if pure distilled water was poured on the brick, that water could soak into the brick and mortar, dissolve the salts and then bring them to the surface when the water evaporates.
The efflorescence on my garage floor is caused by snow and slush that contains rock salt used to melt snow on the roads. This saltwater drips from the underside of my car and soaks into the concrete of my garage floor. As the water is drawn to the surface to evaporate, the water goes into the air, but it leaves behind fluffy salt crystals.
The only way to solve the problem is keep the brick from getting wet. When salts do appear, brush them off with a stiff brush while the brick is dry. Do not wet the salts. That just drives them back into the brick and mortar.