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Cracks in Walls: When to Worry

Almost every house gets wall cracks. The direction, width and location tell you whether yours is cosmetic or a sign of something bigger.

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

Types of cracks in walls

VerticalCommon in drywall, often at seams or above doors. Usually settling or shrinkage.
DiagonalOften from door and window corners as the house settles. Watch the width and growth.
HorizontalIn drywall, often a seam. In masonry or foundation walls, more concerning.
Stair-stepIn brick or block, follows mortar joints. Can indicate foundation settlement.

When to worry about cracks in walls

Usually cosmetic:

  • Hairline cracks along drywall seams, at corners, or above doors and windows
  • Cracks where the wall meets the ceiling that open in winter and close in summer (often truss uplift)
  • Fine cracks in plaster in an older house

Get them checked:

  • Cracks wider than about 1/8", or that reopen after repair
  • Diagonal cracks with doors or windows that stick nearby
  • Several new cracks appearing over a short time
  • Cracks matched by sloping floors, or by cracks in the foundation below
  • Stair-step cracks in exterior brick, especially over 1/4"

Not sure? Run your crack through the Crack Checker.

Why walls crack

  • Settlement: normal in new and old houses alike, especially in the first few years
  • Humidity and temperature: framing lumber swells and shrinks with the seasons
  • Truss uplift: roof trusses arch slightly in winter and pull the ceiling up at interior walls
  • Poor taping: drywall joints with too little compound or tape crack easily
  • Foundation movement: less common, but shows up as diagonal cracks plus sticking doors

How to fix cracks in walls

Drywall cracks

  1. Widen the crack slightly into a shallow V with a utility knife, and remove loose material.
  2. Cover it with fiberglass mesh tape, or paper tape bedded in compound.
  3. Apply two or three thin coats of joint compound, feathering each wider than the last.
  4. Sand smooth, prime and paint.

For recurring cracks at wall-ceiling corners, a flexible caulk or a crown molding fixed only to the ceiling hides seasonal movement better than compound.

Plaster cracks

Fill fine cracks with a setting-type joint compound or a plaster patch. If the plaster is loose or bulging, it has come away from the lath. Reattach it with plaster washers before patching.

Brick and stucco cracks

Repoint cracked mortar joints with matching mortar. Fill fine stucco cracks with an elastomeric stucco patch. If brick cracks are widening, displaced or stair-stepped, get the foundation checked first.

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