Before specifying mortar for a project
or using it in the field, it’s
important to understand why mortar
performance is vital to the successful
performance of masonry and how the
ingredients in mortar affect its performance.
Mortar is the material that
binds masonry units and binds joint
reinforcement and connectors to
the units. It’s also used as a spacer
between units and as a means of leveling
and plumbing the units.
More important, mortar plays a
crucial role in resisting water penetration.
In a typical clay masonry
wall (or in a water-repellent-treated
concrete masonry wall), water does
not significantly permeate the
masonry units or the mortar.
However, it may penetrate the interface
between mortar and masonry
unit if the bond between