How long does a concrete crack injection repair last in NB winters?

A properly done concrete crack injection repair can last 10–25 years in New Brunswick conditions — but the longevity depends heavily on what caused the crack and whether that cause has been addressed. Epoxy injection repairs on stable, structural concrete typically outlast the surrounding concrete. Polyurethane foam injection repairs in foundation walls are also long-lasting for waterproofing, but they're more flexible than epoxy and designed to move slightly with the concrete.

There are two main injection materials used in NB:

Epoxy injection bonds the crack faces together and restores the concrete to near-original strength. This is the correct choice for structural cracks — hairline to 1/2 inch wide — in foundations, beams, and walls where you need to restore load-carrying capacity. Epoxy-injected cracks in stable foundations routinely last 20+ years because the repair is actually stronger than the surrounding concrete. The limitation: epoxy is rigid. If the crack is caused by ongoing movement (settlement, active frost heave, hydrostatic pressure), the repaired crack will likely re-open adjacent to the injection — the concrete will crack again at the next weakest point.

Polyurethane foam injection expands when it contacts moisture, filling irregular crack channels and creating a flexible, waterproof seal. This is the go-to for stopping active water infiltration through foundation cracks. It's not a structural repair, but for waterproofing it's highly effective and accommodates slight movement better than epoxy. Polyurethane crack injection in NB foundations typically lasts 10–20 years when properly done.

The Key Variable: Is the Crack Still Moving?

NB's 4–5 foot frost depth creates significant soil movement every spring and fall as the ground freezes and thaws. Cracks caused by frost heave on footings that were set too shallow will continue to move every year — no injection repair will hold permanently in that scenario because the root cause is structural. Before investing in crack injection ($500–$1,500 per crack professionally done), it's worth having a contractor determine whether the crack is dormant (no longer moving) or active.

Dormant cracks in stable foundations — the most common type in NB homes — are excellent candidates for injection repair and typically hold for many years with no issues. Active cracks may need the underlying cause addressed first: improper drainage corrected, foundation underpinning added, or frost-damaged footings replaced.

For DIY crack injection, epoxy injection kits are available at building supply stores for $40–$80 and work reasonably well on hairline to 1/4 inch cracks in stable slabs. For anything wider, moving, or in a foundation wall carrying structural load, professional injection is the better call. New Brunswick Concrete can connect you with experienced foundation repair contractors across Moncton, Fredericton, Saint John, and beyond — get a professional assessment before deciding on repair vs. replacement.