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Normal Foundation Cracks (with Pictures)

Compare your crack with these diagrams of typical normal and concerning foundation cracks.

By the CrackAdvise team · Updated November 3, 2026 · How we write

These are simplified diagrams, not photos of a specific house. Use them to identify the pattern, then confirm with the Crack Checker or a professional.

Usually normal

Thin vertical shrinkage crackEven width, under 1/8", often near windows or mid-wall. Very common in poured concrete.
Hairline map crackingFine random cracks on the surface of walls or slabs, from curing and surface drying.
Cold jointA straight line where two separate concrete pours met. It looks like a crack but is a construction seam.

Worth watching

Diagonal crackOften minor settlement. Concerning if it's over 1/8", wider at one end, or growing.

Get these checked

Horizontal crackUsually soil pressure on the wall. See an engineer, especially if the wall bows.
Stair-step crack in block or brickCan indicate settlement or wall movement, especially over 1/4".

A normal crack in five checks

  1. It's thinner than 1/8"
  2. It's vertical, or close to it
  3. Both sides are flush. Run a fingernail across it.
  4. It hasn't grown in six months of monitoring
  5. There are no other symptoms: no sticking doors, sloping floors or bowing walls

If your crack passes all five, it's very likely normal. Seal it if water gets in, and keep the dated pencil marks so you'd notice any change.

Foundation cracksHow to read foundation cracks: vertical, horizontal, diagonal and stair-step cracks, width thresholds,…Vertical foundation cracksVertical cracks in poured concrete foundations are usually shrinkage cracks. Learn when they're harmless,…Horizontal foundation cracksHorizontal cracks in foundation and basement walls usually mean soil pressure. Learn the causes, warning…