Red Seal Bricklayer Practice Exam

How does efflorescence typically occur?

1. From excessive moisture in the air

2. From water evaporating from brick surfaces

3. From improper mixing of mortar

4. From bricks absorbing too much water

The correct answer is: From water evaporating from brick surfaces

Efflorescence typically occurs from water evaporating from brick surfaces. This phenomenon arises when soluble salts that are present in the brick, mortar, and surrounding materials are carried to the surface by moisture. When water evaporates, these salts are left behind, creating white, powdery spots on the brick's surface. This can often be mistaken as a sign of damage, but it's a common occurrence in masonry. While the other options touch on relevant aspects of moisture and brickwork, they do not directly address the specific process that leads to efflorescence. Excessive moisture in the air can contribute to the overall moisture levels in masonry structures, and bricks absorbing too much water can also facilitate the movement of salts. However, the key factor is that it is the evaporation of water from the brick surfaces that results in the visible buildup of salts. Improper mixing of mortar might affect the strength and bonding of a structure but does not specifically cause efflorescence. Understanding the direct relationship between evaporation and the appearance of salts helps clarify how efflorescence occurs in masonry.