Diagnose whether masonry step cracking is normal thermal/moisture movement, ordinary building settlement, or a structural problem requiring a structural engineer

Steps

1. Document the crack pattern precisely: location, width, whether it's stair-stepped through mortar joints (typical of differential movement) versus cutting through the brick units themselves (more concerning)
2. Measure current crack width and install a simple monitor (tell-tale, crack gauge, or dated pencil marks) to determine whether the crack is active/widening or dormant/stable
3. Correlate crack location with likely causes: cracks above openings often relate to lintel deflection, cracks near corners/grade often relate to differential foundation settlement, diagonal cracks radiating from openings can indicate foundation movement
4. Distinguish cosmetic, long-stable hairline step cracks (common, often not urgent) from cracks that are wide (roughly 1/4 inch or greater), actively growing, accompanied by out-of-plumb walls, or paired with sticking doors/windows
5. Escalate to a licensed structural engineer for any crack that is active, wide, associated with visible wall displacement/bulging, or where the cause (foundation, lintel, or other structural element) is uncertain — do not repair over an undiagnosed active crack
6. Only proceed with cosmetic/crack-stitching repair once the underlying cause is understood to be stable or has been addressed at its source