Understanding Efflorescence: The White Powder on Exterior Stone in California
Executive Summary The white powder on exterior stone is most often efflorescence—salts/minerals carried to the surface by moisture and left behind as water evaporates. The durable resolution is to control moisture entry and drying conditions (irrigation, drainage, joints, and timing), then clean using stone-safe methods that don’t increase porosity or cause etching. Correct Identification Comes […]