Efflorescence occurs when water is found on brick, natural stone or concrete. It looks white and sometimes has a grayish tint. The white appearance is essentially salt deposits that are left behind by water. Sometimes it is just a cosmetic issue while other times it indicates that moisture is intruding on the structure, which can lead to indoor air quality issues and major structural problems.
A home inspector will be able to recognize potential moisture problems during an inspection. The expense of a mold test can be avoided if a professional can identify it as efflorescence. If the substance is pinched between the fingers, it will become a powder if it is efflorescence while mold won’t. Also, it typically forms on inorganic building materials while mold forms on organic ones. Also, efflorescence will dissolve in water and is often white, yellow or brown.
To prevent efflorescence on a structure, a hydrophobic sealant can be applied to the surface to prevent water intrusion. It also will help prevent water from traveling to the surface within the structure. During home construction, it’s important that bricks that are left out overnight are covered to keep moisture away from the brick.