Basement Crack Repair in Toronto: Guide

Basement Crack Repair in Toronto: Stop Leaks and Protect Your Home

Basement cracks are one of the most common issues facing Toronto homeowners. Whether your basement is finished or unfinished, cracks in the walls or floor can lead to water infiltration, mould growth, and structural concerns. Understanding the types of cracks, their causes, and repair options helps you make informed decisions about protecting your home.

Types of Basement Cracks

Wall Cracks:

• Vertical cracks — Most common, usually from concrete shrinkage during curing. Primary path for water entry but generally not structural.
• Horizontal cracks — Most serious type. Caused by lateral soil pressure against the wall. May indicate structural failure.
• Stair-step cracks — Follow mortar joints in block foundations. Indicate differential settlement.
• Diagonal cracks — Usually from uneven settlement. One side of the foundation settling more than the other.

Floor Cracks:

• Hairline floor cracks — Normal shrinkage. Rarely cause water issues unless hydrostatic pressure is high.
• Heaving floor cracks — Floor lifting indicates frost heave or clay expansion under the slab.
• Cove joint leaks — Water entering where the floor meets the wall. The most common source of basement water.

Basement Crack Repair Costs in Toronto

• Crack injection (epoxy or polyurethane): $300–$600 per crack
• Interior drainage membrane: $2,000–$5,000
• Exterior waterproofing (per crack): $1,500–$3,500
• Cove joint drainage system: $3,000–$8,000
• Interior weeping tile system: $4,000–$10,000
• Exterior weeping tile replacement: $8,000–$15,000
• Sump pump installation: $1,200–$2,500 (see our [sump pump guide](/blog/sump-pump-installation-cost-toronto))
• Carbon fibre reinforcement: $500–$1,000 per strip
• Foundation underpinning: $500–$1,200 per pier

Repair Methods Explained

Polyurethane Crack Injection: The most common repair for leaking wall cracks. A flexible polyurethane foam is injected into the crack under pressure, expanding to fill the entire crack from inside to outside. The foam remains flexible to accommodate minor foundation movement — ideal for Toronto's freeze-thaw cycles. Takes 2–3 hours per crack. Epoxy Crack Injection: Best for structural repairs where rigidity is needed. Epoxy bonds permanently to concrete and restores structural integrity. Not as flexible as polyurethane, so better for non-moving cracks. Takes 2–3 hours plus 24-hour cure time. Exterior Excavation and Membrane: The most thorough waterproofing approach. The exterior of the foundation wall is excavated to the footing, cleaned, and coated with a rubber or asphalt waterproofing membrane. Drainage board and new weeping tile are installed. Most expensive but most comprehensive. Interior Drainage System: A drainage channel is installed along the interior perimeter of the basement floor, collecting water and directing it to a sump pit. Combined with a sump pump, this system manages water pressure without exterior excavation.

Why Toronto Basements Crack

Clay Soil: The GTA sits on expansive clay soil that swells when wet and shrinks when dry. This seasonal movement puts enormous pressure on foundation walls. Neighbourhoods in Mississauga, Brampton, Scarborough, and North York are particularly affected. Freeze-Thaw Cycles: Toronto experiences over 50 freeze-thaw cycles per year. Water in the soil freezes, expands, and pushes against foundation walls. When it thaws, it settles, creating a pumping action. Hydrostatic Pressure: After heavy rain or snow melt, water saturates the soil around your foundation. This creates hydrostatic pressure that forces water through any crack, gap, or porous concrete. Tree Roots: Large trees near your foundation can extract moisture from clay soil, causing it to shrink and create voids under the foundation, leading to settlement cracks. Age: Concrete weakens over time, and older Toronto homes (pre-1970s) often have lower-quality concrete or block foundations more prone to cracking.

Prevention Tips

• 1. Maintain proper grading — Ensure soil slopes away from the foundation
• 2. Keep eavestroughs clean — Direct water away from the foundation (see our [eavestrough guide](/blog/eavestrough-repair-installation-gta))
• 3. Extend downspouts — Minimum 6 feet from the foundation
• 4. Manage landscaping — Keep trees 10+ feet from the foundation
• 5. Install a sump pump — Essential for Toronto homes prone to water issues
• 6. Monitor cracks — Mark and measure cracks annually to detect growth

When to Call a Professional

Contact a professional immediately if you notice:

• Active water leaking through a crack
• Horizontal cracks in your basement wall
• Cracks wider than 1/4 inch or growing
• Bowing basement walls
• Musty odour or visible mould near cracks
• White mineral deposits (efflorescence) on walls

GTA Service Areas

We repair basement cracks across the Greater Toronto Area including Toronto, Mississauga, Brampton, Vaughan, Richmond Hill, Markham, Oakville, Burlington, Ajax, Pickering, and Whitby.

Get Your Basement Assessed

Worried about basement cracks? Call 289-212-2345 for a professional assessment. We will inspect your basement, identify the source of water entry, and recommend the most cost-effective repair method.

Related guides: [foundation crack repair](/blog/foundation-crack-repair-toronto), [sump pump installation](/blog/sump-pump-installation-cost-toronto), and [basement renovation costs](/blog/basement-renovation-cost-toronto-2026).

Frequently Asked Questions

How much does basement crack repair cost in Toronto?

Crack injection costs $300–$600 per crack. Interior drainage systems cost $3,000–$10,000. Exterior waterproofing runs $1,500–$3,500 per crack or $100–$250 per linear foot for full perimeter.

Are basement cracks serious?

Vertical hairline cracks are usually cosmetic. Horizontal cracks, wide cracks, and any crack actively leaking water require professional attention. When in doubt, get an assessment.

Will basement crack repair stop my basement from leaking?

Yes, professional crack injection has a 95%+ success rate for stopping water through wall cracks. For cove joint leaks, an interior drainage system is typically recommended.

How long does basement crack repair take?

Crack injection takes 2–3 hours per crack. Interior drainage systems take 2–3 days. Exterior waterproofing takes 3–5 days depending on the scope.

Does home insurance cover basement crack repair?

Standard insurance usually does not cover cracks from settling or aging. Sudden water damage (burst pipe, sewer backup) may be covered. Call 289-212-2345 to discuss your situation.