Signs of Foundation Problems: What to Look For Inside, Outside and Below

Last reviewed October 28, 2026 · 4 sources cited

No single sign proves a foundation problem, and most cracks and sticking doors have ordinary causes. What matters is the pattern: several signs in the same part of the house, getting worse over months, are what justify a professional evaluation.

The signs inspectors treat as evidence of movement

InterNACHI's inspector-training material lists these as settlement signs: vertical distortion and cracking of masonry walls, warped interior and exterior openings, sloped floors, and sticking doors and windows.^[1] The Colorado Geological Survey adds cracks in basement and garage floors, driveways, sidewalks and walls near door and window corners, and movement in furnace plenums and basement utility lines.^[2]

The ASCE Texas Section guidelines, written for engineers evaluating houses, name corroborating indicators: uneven brick courses, poorly aligned doors, out-of-level cabinets, countertops or trim, and cracking of wall finishes. They also caution that some of these signs do not by themselves prove inadequate performance.^[3]

Inside the house

• Cracks in drywall or plaster, especially running diagonally from the corners of doors and windows. See foundation crack types for how to read them.
• Doors and windows that stick, rub or will not latch, particularly when the change is new. See sloping floors and sticking doors.
• Floors that slope, dip or feel uneven, or gaps between baseboards and the floor.
• Gaps where walls meet ceilings, floors or cabinets, or trim that has pulled apart.
• Cracked floor coverings such as tile that has split along a line.

Outside the house

• Cracks in brick, stone veneer or mortar, particularly stair-stepped along mortar joints or wider at the top or bottom.
• A chimney, porch, step or addition pulling away from the main wall. InterNACHI notes nearly vertical cracks at the joints of bay windows, porches and additions can indicate differential settlement.^[1]
• Cracks in a driveway, garage floor, sidewalk or patio near the house.
• Soil pulling away from the foundation, or ground that slopes toward the house.

In a basement or crawl space

• Horizontal or sweeping cracks, or a wall that bulges. See bowed basement walls.
• Standing water, damp walls, white mineral deposits or a musty smell. See crawl space problems.
• Piers that lean, sit unevenly, or have gaps under the beams above them. InterNACHI notes settlement or rotation of a pier footing causes lowering or tilting and loss of bearing.^[1]

What is probably not a foundation problem

Hairline cracks in drywall are common and often follow framing and humidity changes rather than foundation movement. Doors can stick in humid weather because wood swells. Shrinkage cracks in new concrete are normal; the concrete industry's technical sheet on basement walls states that cracking "is not necessarily a sign of poor materials or workmanship or a structural problem."^[4] The point of the checklist is to notice patterns, not to alarm.

How to track what you see

1. Photograph each crack next to a ruler or coin, with the date visible.
2. Mark the ends of a crack with a pencil and date. A crack that grows past its marks is active.
3. Check seasonally. InterNACHI notes cyclical movement can take six months or more to measure, and that a clean, fresh-looking crack suggests recent movement while a dirty or previously filled crack may be inactive.^[1]
4. Keep the record. An engineer, inspector or insurer will find it useful, and it helps separate seasonal change from progressive movement.

What to do next

If you see a cluster of signs, the next step is an independent evaluation by a licensed structural engineer, not a repair quote. See do you need a structural engineer? and how to read an inspection report.