A technician cleans the crack, bonds a line of plastic injection ports down its length, and seals the surface with a fast-setting paste so the resin cannot escape. Low-pressure resin is then pumped into the lowest port until it travels up and out of the next one, and so on up the wall — which is how we know the crack is filled through its entire thickness, not just skinned over on the inside face. The surface seal and ports are removed or trimmed once the resin has cured. The whole process is done from inside the basement: there is no excavation, no damage to gardens, decks or walkways, and most single cracks are finished in one visit.

Polyurethane is a flexible, water-activated resin that foams and expands on contact with moisture. It is the right choice for a crack that is actively leaking or that still moves slightly with the seasons, because it stays flexible and keeps sealing as the crack breathes. Epoxy is a rigid structural adhesive that effectively welds the two faces of the crack back together and restores the wall’s strength — the right choice for a dry, stable crack where structure, not just water, is the concern. Using epoxy on a moving crack is the classic mistake: the rigid resin holds but the concrete simply cracks again beside it. Matching resin to crack behaviour is the part a homeowner kit cannot judge and an experienced crew can.

Every additional crack on the same visit is 5% off, and every repair carries a transferable lifetime warranty.

Injection seals a crack through a wall. It cannot seal water that is not coming through a crack. If your basement is taking on water at the joint where the floor meets the wall (the cove joint), over the top of the foundation, or up through the slab, injection will not stop it — and anyone who injects a wall crack to “fix” a cove-joint leak has sold you a repair that was never going to work. Those problems need interior drainage or exterior solutions instead. Similarly, a wall that is bowing or has a horizontal crack from soil pressure is a structural question for an engineer before it is a sealing question. On a free assessment we tell you which of these you actually have, even when the answer is that you do not need us.

A professional polyurethane injection runs $750–$1,000 per crack and an epoxy repair $850–$1,500, each with a transferable lifetime warranty and done in one visit. A hardware-store injection kit runs roughly $40–$120, which looks cheaper until you account for what the kit cannot do: judge the resin, reach full depth under proper pressure, or carry a warranty. The common outcome is a crack that re-leaks within a season or two, at which point you pay for the professional repair anyway — now on top of the kit and the water damage in between. For a single straightforward crack a kit can hold; for a crack that is leaking, moving, or near anything finished, the professional repair is usually the cheaper number over any real time horizon.

Pricing and discount figures on this page are our own published rates, current at the review date above. The DIY benchmark comes from our kit-vs-professional comparison. Resin behaviour reflects manufacturer technical practice for hydrophobic polyurethane and structural injection epoxy as applied by our crews; failure patterns are first-party field observations from repairs across Toronto, the GTA and Southern Ontario.