What causes cracks in masonry walls?

Several factors can cause cracks in commercial masonry walls, and understanding these underlying issues is critical for long-term building protection. Structural movement, such as foundation settlement or shifting due to load changes, is a common contributor. Older buildings or those with insufficient support can be especially vulnerable to this type of cracking.

Moisture infiltration is another significant cause. Water can enter through damaged joints, failed sealants, or porous masonry units. In New England, exposure to seasonal freeze-thaw cycles is especially problematic. Water trapped within masonry expands as it freezes, then contracts during thawing, subjecting the wall to repeated stress and often resulting in cracks, spalling, or dislodged units. This is a particular concern for historic structures, which may have more porous materials or aging mortar.

Thermal expansion and contraction due to temperature swings can create additional stresses on the building envelope, particularly if expansion joints or control joints are missing, improperly installed, or deteriorated. Masonry walls without proper allowance for movement can develop cracking as materials expand and contract through New England seasons.

Construction or workmanship issues, such as improper mortar mix, inadequate reinforcement, or rushed installation, may also reduce masonry durability. Over time, these factors can lead to shrinkage cracks or separation between courses.

Commercial properties should address masonry cracks promptly because they compromise waterproofing performance and structural integrity. Even small cracks can allow water intrusion, leading to further deterioration, corroded steel reinforcement, mold, or additional structural issues. Routine inspection, particularly before and after winter, helps identify early signs of movement or moisture ingress.

Professional evaluation is recommended to determine the root cause and appropriate repair scope. Solutions might involve repointing, crack injection, masonry stabilization, or upgrading expansion joints. Preventative maintenance and long-term planning are essential to protect building assets, especially in challenging New England weather conditions.