Foundation settling or a sinking corner

Symptoms

• One corner or section of the house appears lower than the rest
• Doors and windows in that area stick or won't latch
• Diagonal or stair-step cracks in walls near the corner

Likely causes

• CommonExpansive or shifting soil under the foundationClay-heavy soils expand when wet and shrink when dry, which can unevenly move a foundation over time.
• CommonPoor drainage concentrating water at one cornerDownspouts or grading directing water to one spot can erode or soften soil there specifically.
• PossibleInadequate original footing depth or designSome older or poorly built foundations weren't designed for the soil conditions present.

What to do

1. Use a level or a laser level along the foundation and floors to confirm and document the extent of the unevenness.
2. Check gutters, downspouts, and grading near the affected corner, since fixing drainage is a common first, lower-cost step.
3. Photograph related interior cracks, gaps, or sticking doors and windows to share with a specialist.
4. Avoid planting large trees close to the foundation, since roots can worsen soil moisture swings.
5. Get a structural engineer's evaluation before assuming you need underpinning or piers, since the fix depends heavily on the actual cause.
6. Follow the recommended repair, which might range from improved drainage to helical piers or underpinning.
7. Monitor with photos and measurements over time even after repair to confirm stability.

Tools and parts

• 4-foot level or laser level
• Camera

When to call a pro

Call a structural engineer for an independent evaluation, then a foundation repair contractor for the fix they recommend.

Safety