Efflorescence is the result of mineral salts deposited on the surface of stucco, EIFS, concrete or masonry. These deposits are typically harmless but can detract from the structure’s aesthetics.
Mineral salts may be found in the materials used in making stucco. Even the water used in mixing these materials may contribute to efflorescence. Typically, the more refined the component, the less likelihood salt will be present. Care must be taken when handling stucco materials on the jobsite to prevent the unintentional addition of mineral salts.