Analyzing Foundation Cracks

Analyzing Foundation Cracks

Crack Appearance

Vertical or Diagonal Cracks in a foundation wall. Cracks start at floor and run to ceiling. Cracks are wider at the top or the bottom.

Possible Cause

Vertical movement between the two pieces of foundation. Crack is the hinge. Poor fill, soil creep, erosion, etc. are possible causes.

Crack Appearance

Horizontal Crack in a foundation wall. Commonly seen in concrete block walls. Crack is usually 4 to 5 feet off the floor.

Possible Cause

Poorly designed foundation wall. Wall is actually a retaining wall trying to hold back dirt from falling into basement. Can be fixed with beams or helical piers.

Crack Appearance

Stair stepped cracks in a block foundation or in brickwork above a foundation. Cracking often begins at a window or door corner.

Possible Cause

Foundation is either settling or heaving. Vertical displacement between two or more sections is occurring. Must be stabilized before masonry repair begins.

Crack Appearance

Hairline cracks around basement windows or in basement walls. Cracks appear not to get larger. Usually occurs weeks or months after foundation is poured.

Possible Cause

These are likely shrinkage cracks caused by water loss when foundation was curing. Usually not a structural problem unless foundation begins to move.

Crack Appearance

Interior plaster or drywall cracks above doors, windows or archways. No apparent foundation cracks.

Possible Cause

These are most likely seasonal cracks caused by lumber shrinking and swelling. Structural problems are probably not present.

Related Column: Foundation Cracks

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