What masonry strategy reduces potential efflorescence in a Masonry wall assembly?

• A. Increasing cement content
• B. Using units with higher porosity
• C. Reducing the salts and other dirty ingredients in the masonry assembly
• D. Sealing all joints with epoxy at construction

Answer: (C)

Efflorescence happens when soluble salts in the masonry materials dissolve in moisture moving through the wall and then crystallize on the surface as the water evaporates. The most effective way to reduce it is to minimize the source of those salts by using masonry units and mortars with low soluble salts and by removing impurities before assembly. Reducing the salts and dirty ingredients in the masonry assembly cuts the amount of soluble salt available for transport, so less salt is deposited on the surface. In contrast, increasing cement content can raise soluble compounds, higher porosity allows more moisture—and thus more salt movement—through the wall, and sealing joints with epoxy can trap moisture and salts rather than prevent them.