Florida Home Inspector Practice Test 2025 – Comprehensive Exam Prep

Horizontal cracks in masonry walls are commonly associated with rusting steel lintels. When steel supports embedded in masonry become corroded, they expand due to the oxidation process. This expansion can exert significant pressure on the surrounding masonry, leading to horizontal cracking. These cracks often appear near the lintel area, where the support is stressed the most.

While other factors can contribute to masonry issues, the relationship between rusting steel and the resulting structural deformation is a direct cause of horizontal cracking. For instance, soil erosion and improper design can lead to other types of structural problems, like settling or misalignment, while seasonal weather changes may cause thermal expansion or contraction, potentially influencing vertical cracks more than horizontal ones. Understanding the specific mechanics of why lintel rusting leads to horizontal cracks is crucial for identifying and addressing masonry wall issues effectively.