Efflorescence is a fine, white, powdery deposit of water-soluble salts left on the surface of masonry as the water evaporates. These efflorescent salt deposits can develop when three conditions exist: 1) water-soluble salts must be present, 2) sufficient moisture in the wall to dissolve the salts into a soluble solution must also be present and 3) there must be a path for the soluble salts to migrate through to the surface where the moisture can evaporate leaving the salt deposit or efflorescence on the masonry. Almost all basement walls eventually develop a small amount of efflorescence and limited deposits, especially in older construction are generally not a cause of concern. But when it is excessive (as pictured here), especially in a newer building, it may indicate a moisture infiltration problem that needs to be corrected.

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