If your concrete basement walls have a white chalk-like residue on them, you may be at wits end after realizing that wiping it off won't keep it from coming back. This residue is called efflorescence, and it will continue to appear due to water infiltration. Fortunately, there are a few things you can do to prevent efflorescence from reoccurring. Here's what you need to know. 

Efflorescence is a sign of water infiltration 

Efflorescence comes from the salt and mineral deposits of water that has infiltrated your concrete. Some amount of efflorescence occurs in all concrete due to the material being mixed with water during the construction phase. However, ongoing accumulations of efflorescence signifies an ongoing problem with water getting into and through your concrete foundation walls due to the infiltration of ground water. 

Water infiltration can lead to capillary action within the walls 

Concrete is porous and acts as a capillary, which means water that infiltrates your foundation walls can move upwards to your home's wooden framing. Since wood is a denser material and not as porous as concrete, the capillary action stops, which causes the water to accumulate when it reaches the wooden structures. This can result in dry rot and corrosion and lead to mold growth. Therefore, if you have ongoing problems with efflorescence, hire a structural engineer to determine whether or not capillary action has affected your home's structure. 

Prevent efflorescence with water sealant paint on the interior basement walls 

To prevent efflorescence from occurring, you'll need to coat the interior basement walls with a water sealant paint. First, however, all traces of efflorescence needs to be removed with an efflorescence etching product or muriatic acid. If you don't, the water sealant paint will not stick to the concrete. Removing efflorescence can be dangerous to those who do not have experience with the chemical products due to the risks of injuries as they are caustic in nature. Therefore, hire a professional residential painting service. 

Reduce water infiltration by installing a French drain 

While sealing the interior walls will prevent efflorescence, you may need to go a step further and have a French drain installed around the exterior perimeter of your home's foundation, especially if the structural engineer has found extensive capillary action. A French drain will reduce the amount of groundwater directly against the exterior side of your concrete foundation walls. It consists of a gravel-filled ditch with a perforated pipe at the bottom to direct water away from your home's foundation.