WHAT IS EFFLORESCENCE?
Efflorescence is a crystalline deposit of alkaline salts. It is usually white and appears on the surface of masonry (concrete, stucco, plaster, concrete blocks, etc.). It frequently causes, what appears to be, white discolorations on colored paint films, blotchy spots and/or streaks.

WHAT CAUSES EFFLORESCENCE?
Efflorescence is caused by moisture migration through the masonry substrate. Once on the masonry surface, the moisture evaporates, depositing the dissolved salts in the form of efflorescence. The degree of efflorescence can be greatly affected by ambient conditions of temperature and moisture. Some areas of the country therefore have more efflorescence than others.

WHAT ARE SOURCES OF MOISTURE?
Rain, water and snow are the primary source of moisture. Other sources include moisture generation from interior activities, ground water wicking and condensation.

HOW DO YOU REMOVE EFFLORESCENCE?
Because most efflorescence salts are water soluble, they can usually be removed by dry brushing and water rinsing. Power washing is also very effective. On more stubborn areas, washing with a dilute (5% to 10%) muriatic acid or vinegar and water solution is effective. Before applying acid, dampen the surface with clean water to prevent absorption into the surface. Follow manufacturer's application and safety directions. Allow
the solution to stand for about five minutes. Brush or power wash stubborn areas. Rinse thoroughly with plenty of clean water.

HOW DO YOU CONTROL EFFLORESCENCE?
Efflorescence can only be controlled by eliminating sources of moisture ingress. Locate and correct sources of moisture ingress such as leaky roofs, flashing, gutters, uncaulked or improperly caulked joints, faulty construction, etc.. Install vents to relieve moisture particularly in problem areas such as bathrooms, kitchens and laundry rooms. Attic
louvers, exhaust fans and dehumidifiers are also helpful. Use vapor-barrier primers when repainting interior areas. Provide a pinhole-free protective paint or coating to exterior surfaces.