Why Is Mortar Cracking on a New Brick Wall?

The phenomenon of mortar cracking on new brick walls can often be attributed to the natural processes of expanding and contracting, which play a significant role in the structural integrity of buildings. In regions like Michigan, where wide temperature ranges and climate changes are prevalent, such issues tend to occur more frequently. The extreme variations in temperature and atmospheric conditions place additional stress on the mortar and brickwork, making them more susceptible to cracking and deterioration. Understanding these underlying causes is crucial in order to address and mitigate the risk of mortar cracking, ensuring the long-term durability of new brick walls in such environments.

Is It Normal for Brick Mortar to Crack?

Cracks in brick mortar can be a common occurrence in many older structures. While some minor cracking may be considered normal due to the natural settling and shrinkage of materials, larger cracks shouldn’t be ignored.

One of the main reasons for mortar cracking is the natural movement of masonry caused by environmental factors. When temperature and moisture levels fluctuate, masonry materials expand and contract. Inadequate drainage or water infiltration can also contribute to cracking as excessive moisture causes the mortar to weaken and deteriorate.

It’s essential to address cracks in brick mortar promptly to prevent further damage. Small cracks can be repaired by reapplying mortar or using specialized sealants. However, larger cracks may require more extensive repairs, such as repointing or replacing damaged bricks. In cases where the cracking is severe or associated with structural issues, it’s advisable to consult a professional mason or structural engineer to assess the extent of the damage and recommend appropriate solutions.

Regular maintenance and inspections can also help identify potential issues before they escalate. Ensuring proper drainage, addressing any water infiltration or moisture problems, and monitoring any signs of movement can help prevent or minimize the occurrence of cracks in brick mortar. Properly maintaining the mortar joints by applying suitable sealants or repointing when necessary can also extend the lifespan of brickwork and reduce the likelihood of cracking.

Hairline cracks in mortar are a common occurrence and shouldn’t raise concerns. These small cracks are typically found between bricks and concrete blocks, and they’re considered normal. However, it’s important to distinguish them from wider cracks that are wider at the top than at the bottom, as these may indicate underlying issues that require attention.

Are Hairline Cracks in Mortar Normal?

These hairline cracks are often caused by the natural expansion and contraction of the materials with temperature changes and the settling of the building foundation. They typically don’t present any structural concerns and can be considered normal wear and tear on the masonry. However, it’s important to monitor these cracks and ensure they don’t worsen over time.

On the other hand, cracks that are wider at the top than the bottom can be indicative of more serious underlying issues. These cracks, known as “step cracks,” can be a sign of foundation settlement or movement. When the foundation of a building settles or shifts, it can cause various structural problems, including these step cracks in the exterior mortar. These cracks may be accompanied by other signs such as uneven floors or doors that no longer close properly.

In such cases, it’s crucial to seek the advice of a professional masonry contractor or structural engineer to assess the extent of the damage and provide recommendations for repair. They may need to perform a thorough inspection to determine the cause of the settlement and propose suitable solutions. Depending on the severity of the issue, repairs could involve stabilizing and reinforcing the foundation or even rebuilding parts of the affected masonry.

It’s worth noting that not all cracks in mortar are created equal, and their potential impact can vary depending on the age and condition of the structure. Older buildings with existing cracks may have gained stability over time, whereas new or rapidly growing cracks should be addressed promptly to prevent further damage. Regular inspections and maintenance can help identify any changes or issues with the mortar, allowing for timely repairs and avoiding potential costly consequences down the line.

In summary, hairline cracks in mortar are generally normal and shouldn’t cause immediate concern. However, cracks that widen at the top should be evaluated by professionals to ensure there are no underlying structural issues. Regular inspections and monitoring are essential to catch any deterioration early and prevent further damage. Remember that when it comes to the stability and integrity of your home or building, it’s always better to be safe than sorry.

How to Monitor and Measure the Severity of Cracks in Mortar

  • Visual inspection: Regularly examine the mortar for any visible cracks.
  • Measuring crack width: Use a crack gauge to measure the width of each crack.
  • Monitoring crack movement: Place reference marks on either side of the crack and periodically measure the distance between them over time.
  • Photographic documentation: Take clear and close-up photos of the cracks to track their progress.
  • Mortar hardness test: Conduct a hardness test on the mortar to determine if it’s become softer or more brittle.
  • Moisture evaluation: Monitor the moisture levels in the mortar as excessive moisture can worsen cracks.
  • Crack mapping: Create a detailed map outlining the location and extent of cracks throughout the structure.
  • Structural analysis: Consult with a structural engineer to assess the severity of the cracks and evaluate their impact on the overall stability of the building.
  • Periodic reevaluation: Regularly revisit the cracks to observe any changes or progression in their severity.


Whether it’s caused by the bricks themselves or the underlying soil, these factors play a significant role in compromising the structural integrity of the mortar. In the case of Michigan homes, which are particularly susceptible due to the wide temperature ranges and varying climate changes in the region, this issue becomes even more pronounced. Recognizing and addressing these challenges can help homeowners and builders ensure the longevity and durability of their brick structures.

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