Why Calgary foundations crack
Calgary sits on expansive clay soils that swell when wet and shrink when dry, with seasonal freeze-thaw adding further movement. Concrete responds by cracking — usually predictably, in patterns inspectors and engineers can read. Almost every Calgary home over 15 years old has at least one visible foundation crack; most are not structural concerns.
Vertical hairline cracks
By far the most common. These often appear within the first two years after construction as concrete cures and the structure settles, then stabilize. A vertical crack narrower than the edge of a credit card (~1.5 mm) with no offset between the two sides and no active water entry is generally cosmetic. Polyurethane injection from the inside runs $400–$900 in Calgary.
Diagonal cracks at openings
Cracks emanating from window or door corners reflect localized stress concentration. If they remain hairline, they're typically cosmetic. If they widen at the top or show offset between sides, they warrant closer evaluation.
Horizontal cracks — call an engineer
A horizontal crack in a basement wall, particularly in the upper third, suggests inward soil pressure — sometimes hydrostatic from poor drainage, sometimes frost-related, sometimes from settled fill against the wall. Horizontal cracks combined with any inward bowing are a structural engineer call, not a homeowner repair.
Stair-step cracks in masonry
These usually reflect differential settlement between two parts of the structure. Whether they matter depends on how much movement is occurring and whether it's ongoing. Photograph with date and a coin for scale to assess change over months.
What the inspection documents
The inspector documents location, orientation, width, and any associated water entry, displacement, or moisture damage. Anything outside normal patterns triggers a recommendation for a structural engineer, who can determine whether intervention is needed and what it should be.
