Foundation Cracks
Cracks in your foundation? Learn which are harmless vs. dangerous, DIY monitoring tips, and repair costs ($500–$15,000).
Typical repair cost: $500–$15000 · DIY difficulty: Professional Only · About N/A.
What usually causes it
- Normal concrete curing
- Soil expansion/contraction
- Poor drainage
- Tree root pressure
- Hydrostatic pressure
- Earthquake/settling
What you need
- Pencil
- Ruler
- Camera
How to fix it yourself
- Identify the crack type: vertical hairline cracks are usually from normal curing and are less concerning
- Horizontal cracks are the most serious — they indicate lateral pressure on the wall
- Stair-step cracks in block walls suggest differential settling
- Mark the ends of each crack with a pencil and date — monitor if they grow
- Measure crack width with a ruler and photograph monthly
- DO NOT attempt to fix structural cracks yourself — cosmetic patching hides the real issue
When to call a pro
Always for horizontal cracks, cracks wider than 1/4 inch, cracks with water seepage, or any crack that is growing. Get a structural engineer (not just a contractor) for an unbiased assessment.