Which design aspect can influence the likelihood of efflorescence in masonry?

The type of mortar used is a crucial design aspect that can significantly influence the likelihood of efflorescence in masonry. Efflorescence occurs when soluble salts present in the masonry or the materials used in construction are drawn to the surface by moisture. Different types of mortar have varying compositions and permeability levels, which can affect how much moisture can pass through them and how much salt can be transported to the surface.

For instance, mortars with higher water retention and lower permeability may retain moisture for longer periods, providing more opportunities for salt to migrate to the surface and crystallize as efflorescence when the water evaporates. Additionally, mortars that contain higher quantities of soluble salts can contribute directly to the efflorescence issue. Therefore, selecting appropriate mortar that minimizes these risks is key to reducing the potential for efflorescence in masonry walls.