Polyurethane Crack Injection Toronto & GTA

If your basement wall is leaking through a crack, polyurethane crack injection is the fastest and most reliable way to stop it. Dryshield performs polyurethane crack injection across Toronto and the GTA every day, sealing foundation cracks from the inside in under two hours — no exterior excavation required. We back every repair with a lifetime transferable warranty.

Polyurethane foam resin expands on contact with moisture, filling the full depth of the crack from interior surface to exterior soil. The cured foam stays flexible, so it moves with your foundation through seasonal thermal cycles and minor settlement without tearing or re-cracking. For Toronto homeowners dealing with an active water leak, polyurethane crack injection is the go-to solution.

Polyurethane crack injection is a method of repairing poured-concrete foundation cracks by injecting a two-component polyurethane resin directly into the crack under controlled pressure. The resin reacts with moisture inside the crack, expanding five to twenty times its original volume. This expansion fills every void — hairline fissures, honeycombing behind the visible crack face, and the full eight-to-ten-inch wall thickness — creating a continuous waterproof barrier.

Unlike rigid epoxy, cured polyurethane retains a rubber-like flexibility. This matters in Toronto where freeze-thaw cycles cause concrete to expand and contract throughout the year. A flexible seal moves with the wall instead of cracking away from it.

Toronto homeowners often ask whether they should choose polyurethane or epoxy for a foundation crack repair. Both methods work, but they serve different purposes. Here is how the two compare:

When Dryshield Uses Each Method

Our technicians assess every crack before choosing a method. For over 90% of residential foundation cracks in the Toronto and GTA area, we recommend polyurethane crack injection because the crack is non-structural and the primary concern is stopping water. When structural repair is needed, we use epoxy injection or combine polyurethane with carbon fibre reinforcing staples to address both waterproofing and structural stability.

Not sure if polyurethane crack injection is right for your situation? Look for these warning signs:

Visible Wall Crack With Water Stains

A vertical or diagonal crack on your basement wall with white mineral deposits (efflorescence) or rust-coloured staining around it means water has been moving through the crack repeatedly. Polyurethane injection seals the crack permanently and stops the mineral buildup.

Active Water Leak During Rain

If water drips or streams through a crack during or after heavy rain, that crack connects to the exterior soil and hydrostatic pressure pushes water through. Polyurethane foam injection works even while the crack is actively leaking — the resin reacts with the water to cure faster.

Damp Smell or Mould Near a Wall Crack

Moisture seeping through a hairline crack can feed mould growth behind drywall without any visible water on the floor. If you notice a persistent musty smell near a basement wall, a hidden crack may be the source. Polyurethane injection seals the entry point and cuts off the moisture supply.

Previous Repair That Failed

Hydraulic cement patches, caulking, and waterproof paint are temporary surface fixes that eventually fail because they do not fill the crack through the full wall thickness. If a previous repair is leaking again, polyurethane crack injection is the permanent solution because the expanding foam fills the entire crack from inside face to exterior soil.

Step 1 — Crack Assessment

Our technician examines the crack to determine its cause, direction, width, and whether it is structural or non-structural. This assessment dictates whether polyurethane, epoxy, or a combination approach is appropriate.

Step 2 — Surface Preparation

The team cleans the crack face with a wire brush to remove loose concrete, old paint, and mineral deposits. Clean concrete ensures proper adhesion of the surface-seal paste and injection ports.

Step 3 — Port Installation

Injection ports are placed along the length of the crack, spaced roughly four to six inches apart. In some cases, mechanical packers are drilled at a 45-degree angle directly into the crack for high-pressure injection.

Step 4 — Surface Seal

A fast-setting epoxy paste seals the crack surface between ports. This paste acts as a dam, keeping the injected polyurethane inside the crack during the injection process.

Step 5 — Polyurethane Injection

Starting at the lowest port, the technician injects two-component polyurethane resin under controlled pressure. The foam travels through the crack, expanding and displacing water as it goes. Injection continues port by port, moving upward, until resin appears at the next port — confirming complete fill.

Step 6 — Cleanup & Warranty

After the resin cures (typically 15-30 minutes), the technician removes the ports and smooths the surface. You receive a written lifetime transferable warranty.

A standard single-crack polyurethane injection on a residential foundation wall costs $750 to $1,000 in the Toronto and GTA market. Most homeowners pay around $750 to $1,000 for a typical eight-foot vertical shrinkage crack. Multiple cracks on the same visit are usually discounted.

Cost Factors

Several factors influence the final price: crack length and width (longer or wider cracks require more resin), crack location (corners and obstructed areas take longer), whether the crack is actively leaking (high-flow leaks may need additional material), and accessibility (finished basements may require removal of a small section of drywall near the crack).

Compared to Other Waterproofing Methods

Freeze-Thaw Cycles

Toronto experiences over 50 freeze-thaw cycles per year on average. Each cycle causes soil and moisture around your foundation to expand and contract, placing repeated stress on the concrete. Over time, this stress causes shrinkage cracks to develop — the most common type of residential foundation crack.

Clay Soil and Hydrostatic Pressure

Much of the GTA sits on clay-heavy soil that retains water after rain and snowmelt. Saturated clay expands and presses against foundation walls, creating hydrostatic pressure that pushes water through any existing crack. Polyurethane crack injection stops this water intrusion by sealing the crack from the inside.

Aging Housing Stock

Many Toronto neighbourhoods — Etobicoke, Scarborough, North York, The Beaches, High Park — have homes built in the 1950s through 1980s. After 40-70 years of exposure to frost cycles and soil pressure, foundation cracks are virtually inevitable. Polyurethane injection repairs these cracks without disturbing landscaping, driveways, or the home exterior.

A properly performed polyurethane crack injection is a permanent repair. The cured polyurethane foam does not degrade, shrink, or dissolve over time. Its flexibility allows it to absorb minor foundation movement without losing its seal.

Dryshield backs every polyurethane crack injection with a lifetime transferable warranty. If you sell your home, the warranty transfers to the new owner — adding resale value and peace of mind. In over 20 years of performing crack injections across Toronto and the GTA, the vast majority of our polyurethane repairs have held permanently without requiring re-injection.

Polyurethane crack injection is not limited to residential homes. Dryshield also performs polyurethane foam injection on commercial and industrial concrete structures across the GTA, including parking garage decks and walls, condominium underground parking levels, elevator pits, mechanical room floors, warehouse foundations, retaining walls, and water treatment structures.

High-pressure injection with mechanical packers allows our technicians to seal cracks in thick commercial-grade concrete up to 24 inches. For commercial property managers and contractors in Toronto looking for a fast turnaround, polyurethane crack injection is often completed in a single visit with no disruption to building operations.

How much does polyurethane crack injection cost in Toronto?

A single-crack repair typically costs $750 to $1,000 in the Toronto area. Most homeowners pay $750–$1,000 for a standard eight-foot vertical crack. Multiple cracks on the same visit are usually discounted. Dryshield provides free, no-obligation estimates for all crack injection work.

How long does polyurethane crack injection take?

Most single-crack repairs take 1 to 2 hours from start to finish. The polyurethane resin begins curing within minutes of injection and reaches initial set in 15-30 minutes. You can resume normal use of the basement immediately after the technician leaves.

Does polyurethane crack injection work on actively leaking cracks?

Yes. Polyurethane is specifically designed for wet and actively leaking conditions. The resin is water-activated — moisture inside the crack accelerates curing and expansion. This is one of the main advantages polyurethane holds over epoxy, which requires a dry crack surface.

Is polyurethane crack injection a permanent fix?

Yes. Properly injected polyurethane foam does not degrade, shrink, or wash away over time. The flexible seal moves with your foundation through freeze-thaw cycles without cracking. Dryshield backs every injection with a lifetime transferable warranty.

What is the difference between polyurethane and epoxy crack injection?

Polyurethane is flexible, water-activated, and expands to fill voids — ideal for waterproofing non-structural cracks. Epoxy is rigid with high tensile strength (7,000 psi) — ideal for structural repairs on dry cracks. Over 90% of residential foundation cracks in Toronto are non-structural, making polyurethane the more common choice.

Can polyurethane injection fix a crack that was previously repaired?

Yes. Failed hydraulic cement patches, caulking, or previous injection repairs can be re-done with polyurethane. The expanding foam fills around and past old repair material to seal any remaining voids.

What is the difference between polyurethane foam and polyurethane resin?

In foundation crack repair, the terms are often used interchangeably. Technically, polyurethane resin is the liquid injected into the crack, and polyurethane foam refers to the expanded state after the resin reacts with moisture. The result is the same — a flexible, waterproof seal through the full wall thickness.

Do you perform polyurethane crack injection outside Toronto?

Yes. Dryshield services the entire GTA and surrounding regions including Mississauga, Brampton, Oakville, Burlington, Markham, Richmond Hill, Vaughan, Scarborough, North York, Etobicoke, Barrie, Hamilton, and beyond. Call 1-800-277-5411 for a free estimate in your area.

Does the City of Toronto offer rebates for crack injection?

The City of Toronto Basement Flooding Protection Subsidy Program reimburses homeowners up to $3,400 for qualifying drainage and waterproofing work. While crack injection alone may not qualify, it is often performed alongside eligible work such as sump pump installation and backwater valve installation. Dryshield assists with the application process.

Get a free, no-obligation polyurethane crack injection quote from Toronto’s most trusted basement waterproofing contractor. Same-day estimates available. Call 1-800-277-5411 or fill out the form below.