Foundation Repair Cost in Markham

Structural engineer or foundation specialist inspects the cracks, measures deflection (for bowing walls), and determines the cause. Key data: crack width, direction, location (above/below grade), water intrusion, soil type, and drainage conditions. Engineer classifies the damage and recommends repair methods. For settlement or severe bowing, geotechnical testing may be required to assess soil bearing capacity.

Drill 3/8-inch holes into the crack at 8-12 inch intervals, starting at the bottom. Insert injection ports (plastic or metal nozzles). Seal the crack face with epoxy paste to contain the injection. Inject epoxy or polyurethane under pressure (40-60 PSI), starting at the lowest port and working upward. Material flows through the crack and exits the next port up — when it does, cap that port and move to the next. After injection, remove ports and grind flush. Epoxy cures in 24-48 hours; polyurethane expands and cures in 15-30 minutes.

Grind the interior wall surface smooth (removes paint, efflorescence, and rough spots). Apply epoxy adhesive to the wall in vertical strips (6-8 feet apart, centered on the bowing area). Press carbon fiber straps (4-6 inches wide, 1/16 inch thick) into the epoxy, ensuring full contact. Trowel additional epoxy over the straps to encapsulate them. The carbon fiber has 150,000 PSI tensile strength (vs steel at 60,000 PSI) and prevents further bowing. It does NOT pull the wall back — it arrests the movement.

Excavate holes outside the foundation (10-15 feet from the wall) to install earth anchors — steel plates buried 6-8 feet deep. Drill through the basement wall and thread steel rods from the earth anchors to interior wall plates. Tighten the rods to pull the wall back toward vertical. This method can reverse bowing (carbon fiber cannot), but it requires exterior excavation and leaves visible wall plates inside the basement.

Excavate small pits (3x3 ft) at the foundation footing, spaced 6-10 feet apart along the settling section. Use a hydraulic drive to screw helical piers (steel shafts with 8-12 inch helical blades) into the ground, monitoring torque with a gauge. When torque hits the target value (correlated to soil bearing capacity), you've reached competent soil. Attach brackets to the footing and the pier shaft, transferring the load. Slowly hydraulic-lift the foundation back to level (if desired), then lock the brackets. Backfill the pits.

Chip away loose or cracked parging with a hammer and chisel. Clean the concrete surface (pressure wash or wire brush). Apply a bonding agent (liquid adhesive that helps new parging stick to old concrete). Trowel on a 1/2-inch layer of parging mix (cement, sand, lime, and polymer modifiers). Smooth with a trowel and feather the edges to blend into existing parging. Cure for 7 days (keep moist with a sprayer — prevents cracking). Paint or seal once cured.

Install crack monitors (plastic gauges that track crack width changes over time) or take baseline measurements with a ruler and photo. Engineer recommends a monitoring period (6-12 months) to verify the repair arrested movement. If cracks reopen or widen, the root cause (settlement, lateral pressure, drainage) wasn't fully addressed.