Ottawa's geology and climate create unique challenges for home foundations. The city sits on a mix of clay, silt, sand, and bedrock (Leda clay is particularly problematic), and our extreme freeze-thaw cycles — from -35°C to +35°C — subject foundations to constant stress. Leda clay (also called Champlain Sea clay or sensitive marine clay) underlies much of Ottawa and is notorious for its instability. When disturbed or exposed to water, it can lose up to 90% of its strength, causing dramatic sett...
Crack injection (epoxy or polyurethane): $400–$800 per crack. The most common foundation repair in Ottawa. Epoxy injection fills and bonds the crack, restoring structural integrity. Polyurethane injection is flexible (accommodates future movement) and is preferred for active water leaks. A typical Ottawa home may have 2–4 cracks requiring injection. Total: $800–$3,200. Exterior waterproofing: $150–$300 per linear foot. The gold standard for water infiltration. Involves excavating around the fou...
Cracks in foundation walls: Vertical cracks wider than 1/4 inch, diagonal cracks (indicating settlement), or horizontal cracks (indicating lateral soil pressure) all warrant professional inspection. Horizontal cracks are the most serious — they indicate the wall is failing under pressure. Water in the basement: Recurring water after rain or snowmelt, efflorescence (white mineral deposits) on foundation walls, musty odours, or visible mould all indicate water penetration through the foundation. ...
Specialization matters: Foundation repair is highly specialized. General contractors and waterproofing companies may not have the structural engineering knowledge needed for complex foundation issues. For anything beyond simple crack injection, work with a company that specializes in structural foundation repair. Get a structural engineer's opinion: For significant foundation issues ($10,000+ repairs), hiring an independent structural engineer ($500–$1,500 for a foundation assessment) provides ...
Crack injection costs $400–$800 per crack. Interior waterproofing costs $10,000–$22,000 for a full perimeter. Exterior waterproofing costs $20,000–$42,000. Carbon fibre wall stabilization costs $2,000–$8,000 per wall. Underpinning costs $40,000–$100,000+.
Small vertical hairline cracks (under 1/8 inch) in poured concrete are normal shrinkage cracks. Cracks wider than 1/4 inch, horizontal cracks, growing cracks, or cracks with water infiltration require professional assessment.
Exterior waterproofing is the gold standard — it stops water before it reaches the foundation. Interior systems manage water that has already entered. For new water problems, exterior repair is preferred. For managing chronic dampness, interior weeping tile with a sump pump is effective and less disruptive.
Crack injection takes 1 day. Carbon fibre strap installation takes 1–2 days. Interior waterproofing takes 3–7 days. Exterior waterproofing takes 5–14 days (weather dependent). Underpinning takes 2–6 weeks depending on scope.