Foundation
Cosmetic vs. Structural Foundation Cracks
Updated · Holdfast editorial · 2 min read
When is it usually cosmetic?
- Hairline vertical cracks
- No offset
- Not growing
When should you get it checked?
- Horizontal
- Stair-step
- Wider at one end
- Offset or growing
What comes next?
When should you call for an assessment?
- Horizontal cracks in block walls
- Stair-step cracks that widen
- Cracks wider than about 1/4 inch
- One side of the crack offset from the other
- Doors and windows upstairs starting to stick
How do you read a crack?
The direction, width and whether the crack is changing tell you most of what you need to know.
- Hairline vertical cracks in poured concrete: usually shrinkage; seal if they leak
- Stair-step cracks along block mortar joints: settlement or pressure; watch for widening
- Horizontal cracks in block walls: soil pressure pushing the wall; have it assessed
- Cracks wider at one end, or with one side offset from the other: movement
- Any crack that gets wider over months
Why monitor before you decide?
Mark the ends of the crack with a pencil and date it, and photograph it next to a ruler. Check again after the winter freeze and the spring thaw. A crack that hasn't moved is usually a sealing job; one that grows needs a structural assessment.
Call a professional if
- Crack wider than about 1/4 inch
- One side of the crack offset
- Horizontal or stair-step pattern
- Crack getting longer
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About structural foundation crack repairWhat else do people ask about this?
Are vertical cracks in poured walls normal?
Thin vertical shrinkage cracks are common in poured concrete. They're usually cosmetic but can leak and are often sealed with injection.
Can I patch a crack myself?
Hairline cracks can be sealed with DIY kits, but leaking or widening cracks should be assessed first.
Where can I verify this information about your home?
- 1NOAA National Centers for Environmental Information: U.S. Climate NormalsAverage precipitation, snowfall and temperatures for weather stations near your home.
- 2USDA Natural Resources Conservation Service: Web Soil SurveyLook up soil drainage class and shrink-swell potential for any lot in your home.
- 3Federal Trade Commission: Hiring a ContractorWhat to check before hiring: licensing, insurance, written estimates and payment terms.
Every home differs; editorial standards.