Foundation Crack Repair: When a Hairline Crack Becomes a $20,000 Problem

Almost every Markham home over 15 years old has at least one foundation crack. Most are no big deal — IF you fix them early.

Why cracks happen

Concrete shrinks as it cures. Soil shifts seasonally with frost cycles. Minor settling. None of these are catastrophic on their own.

Why they become catastrophic

Once a crack lets water through, freeze-thaw cycles widen it every winter. Water entering the crack rusts any rebar inside, which expands and cracks the concrete further. The crack grows from hairline to finger-width to "I can see daylight."

The fix at the right time

Polyurethane injection. We inject low-viscosity polyurethane that penetrates deep into the crack and expands to fill every micro-fracture. Cures flexible, so it moves with seasonal foundation shifts. $400–$900 per crack. Workmanship warranty.

The cost of waiting

Severe foundation crack repair often involves exterior excavation, structural reinforcement (carbon fibre straps or steel beams), and full membrane re-application. $15,000+ is common.

When to call us

You see ANY crack with: visible width (more than a hairline), water staining around it, efflorescence, or signs of recent widening. Free inspection.

Get a free inspection in Markham

If you've noticed dampness, cracks, or musty smells in your basement, don't wait. We offer free on-site inspections across Markham, Unionville, Cornell, Berczy Village, Cathedraltown, Markville and Thornhill — and our work is backed by a written workmanship warranty.