Sacrificial mortar is mortar intentionally formulated to be softer than the brick or stone units it joins, so the mortar joints wear, crack, and erode first, protecting the brick or stone itself, which is more expensive and harder to replace.
It sounds backwards, but weaker mortar is the goal in most masonry, not a flaw. A wall is designed so the mortar joints take the brunt of stress from moisture, freeze-thaw movement, and minor settling, then get repointed every so often, rather than the brick units themselves absorbing that damage. When mortar is accidentally made too strong, harder than the brick around it, that relationship flips, and the brick starts cracking and spalling instead of the joints.
This is one reason mortar hardness has to match brick age and hardness, especially on older, softer brick common on historic homes in this area. A joint that cracks or erodes over a Blue Ridge winter is doing exactly what it's supposed to, and repointing it is a normal, expected maintenance step rather than a sign something went wrong with the original work.
More masonry vocabulary from the glossary.
The services where this term comes up.
Chelo's Brick & Stone serves Hillsville, Galax, Wytheville, Fancy Gap, and Independence, VA. Call for a straight answer and a free on-site estimate.
