Efflorescence causes and Cures
Is basement dandruff a problem in your home? Are there fine white lines, flaking crystal deposits, or heavy chalky build-ups on your exposed basement walls or floor? These are EFFLORESCENCE, and are sure indications of a basement water problem. In some cases, the height of the indications of efflorescence may indicate the height of water build-up and infiltration along the exterior foundation.
Efflorescence is the salts deposited on masonry or concrete walls or floors. These salts are left behind when water evaporates. Three conditions must be met to create efflorescence. First, water soluble mineral salts must be present. Second, there must be moisture to dissolve the salts. Third, the water/salt solution must have a path through to the surface where the water can evaporate and crystallization can occur.
The mineral salts in mortar, grout, sand and concrete provide for the achievement of the first condition, while the porous nature of concrete, concrete block, brick or stone foundations permit the water-dissolved salts to migrate to the surface. We cannot change either of these conditions. To stop efflorescence, the homeowner must control or eliminate the presence of the water required to dissolve the alkalis.
Some homeowners try washing and this method is often sufficient to remove efflorescence. Commercial cleaners are also available. However, cleaning by either method does not cure the problem. It only removes the symptoms. After cleaning, salt crystals will reappear unless the natural and existing efflorescence chain is broken. And, the added water used in cleaning often causes the deposits to reform more extensively than before cleaning. It is also not a cure-all to seal the wall with a silicone water repellent. The physical requirements for efflorescence still exist. The sealants only trap the salt formations below the surface. Then the expanding salt crystals can cause spalling and small flakes to pop off the walls.
The only sensible decision when you find efflorescence is to inspect and correct the foundation leakage problem before it gets worse.