The 4 Main Reasons Causes Wall Cracks and What to Do With Them

Wall cracks are frustrating, but understanding the cause is the first step to properly repairing and preventing future wall cracks. Here are 4 main reasons for cracks in walls and how to fix them.

1. Settlement cracks
These wall cracks form when a foundation settles unevenly, causing stress on walls. Settlement cracks tend to be vertical and spiderweb out from corners. Repair involves removing baseboards and caulking or patching cracks from the inside. Applying a flexible sealant, then painting over the repair helps prevent future leaks.

2. Shrinkage cracks
These tiny wall cracks form as new drywall or plaster dries out. They usually appear as zig-zag patterns in interiors. To fix, apply drywall patching compound and feather the edges. Then sand any seams smooth and paint. Adding a primer sealer coat before painting helps protect fresh repairs.


3. Thermal cracks
Hot and cold temperatures cause the expansion and contraction of building materials, resulting in wall cracks. Thermal cracks often slant and appear above and below windows and doors. Repairs involve cutting away loose material, filling in with a concrete-like mixture and blending to match the existing texture. Then painting over the repairs with flexible, breathable paint.

4. Vibration cracks
Wall cracks caused by vibrations tend to radiate out from a central point. Sources of vibration can include heavy traffic, equipment or heavy objects striking walls. Repair involves cutting away loose material, filling in cracks with drywall compound or epoxy filler and smoothing. New drywall or plaster may be needed for larger cracks. Then paint for aesthetic purposes.

Once you’ve identified the cause, wall crack repairs require removing loose material, patching, smoothing and painting or coating to match existing walls. Taking steps to prevent further damage after repair will minimize future wall cracks. For the best results with wall crack repairs, consider calling in a professional handyman or contractor. Wall cracks that are not properly repaired can worsen over time, leading to more severe damage and higher repair costs down the road.