Efflorescence is the white chalky powder that you might find on the surface of a concrete or brick wall. Pinched between the fingers, efflorescence will turn into a powder. It can be a cosmetic issue, or it can be an indication of moisture intrusion that could lead to major structural and indoor air quality issues. A home owner needs to understand what efflorescence is in order to recognize potential moisture problems.Building materials, such as concrete, wood, brick and stone, are porous materials. Porous materials can absorb or wick water by a process called the capillary action. As water moves through the porous material, salts can be drawn with it.Concrete, wood, brick, stone and mortar are porous materials that contain salts. The ground in which these materials can come into contact also contain salts. Capillary action can literally suck water and transport it through porous building materials.
INDICATIOS OF MOISTURE::-- Efflorescence is the dissolved salts deposited on the surface of a material (such as concrete or brick) that are visible after the evaporation of the water in which it was transported. The moisture that creates efflorescence often comes from groundwater, but rainwater can also be the source. Efflorescence alone does not pose a major problem, but it can be an indication of moisture intrusion.