Vertical and diagonal hairline cracks are common in poured concrete as it cures and settles, and are usually cosmetic if they stay narrow and dry. Horizontal cracks and stair-step cracks in block walls point to lateral pressure from soil or water and are treated as structural until proven otherwise. A crack that is actively leaking, growing, or wider than about 1/4 inch gets a full assessment before we recommend a repair method.
Bonds structurally with the concrete, best suited to dry, stable cracks where restoring rigidity matters.
Flexes with minor movement and expands to fill the crack, better suited to active leaks and damp cracks.
Chosen on-site based on whether the crack is leaking, still moving, and how wide it is – not a default.
Cracks in block foundations, cracks wider than injection can reliably seal, and cracks tied to a bowing or shifted wall are usually repaired from the outside. That means excavating down to the footing, repairing and waterproofing the wall, and installing or replacing the weeping tile before backfilling. It costs more than injection but addresses the wall as a whole rather than one crack in isolation.
For an interior injection, we clean the crack face, install injection ports along its length, and seal it with epoxy or polyurethane under low pressure so the material fills the crack from the inside out rather than just bridging the surface. Most single-crack jobs are done in a few hours, with curing time afterward before the area can be painted or finished. An exterior repair takes longer since it starts with excavation down to the footing, and we always confirm which approach applies to your specific crack before quoting either one.
Pricing for crack repair depends mainly on whether the fix is interior injection or exterior excavation, and how many cracks are involved on the same wall. An interior epoxy or polyurethane injection typically runs $300 to $1,200 per crack, while exterior excavation and repair for a wider or block-foundation crack runs $1,500 to $3,000 per crack, reflecting the added labour of excavating and waterproofing the wall. We do not offer blanket guarantees on this website – any workmanship warranty on a specific repair is set out in your written quote, job by job, once we’ve confirmed the actual scope.
Once a crack has been properly injected or excavated and repaired, it shouldn’t need ongoing attention, but it’s still worth checking the area during spring thaw and after heavy rain for the first year or two. Keep downspouts extended away from the foundation and make sure grading around the repaired section still slopes away from the house, since poor drainage is the most common reason a nearby area develops a new, unrelated crack later on. If you ever see moisture, staining, or a new hairline crack forming near an old repair, it’s worth a quick look rather than assuming it’s the same issue resurfacing.
Hardware-store crack sealants can look like they’ve solved the problem for a season or two, but most surface-applied products only bridge the visible crack rather than filling it from the inside, so they tend to fail once the foundation moves again with the seasons or once hydrostatic pressure builds up behind the wall. Professional injection forces material into the full depth and length of the crack under controlled pressure, which is why it holds up over freeze-thaw cycles in a way that a bead of exterior caulk generally doesn’t.
Water is getting through, even occasionally, during rain or spring thaw.
The crack is visibly wider than it was a few months ago.
This pattern points to lateral pressure rather than simple shrinkage.
Tell us what you're seeing and where it is on the property.
We inspect the affected area, confirm the cause, and check whether it's still active.
A specific scope of work and price in writing before we schedule anything.
Work is carried out to the agreed scope, then we review it with you and confirm it matches the quote.
Usually not, if it's narrow, dry, and not growing. It's still worth a quick look if you've never had it checked.
Often, for non-structural cracks in poured concrete. Wider, leaking, or block-wall cracks usually need exterior excavation.
Most single-crack injections are completed in a few hours, with curing time afterward before the area can be finished or painted over.
A properly injected or excavated crack shouldn't reopen at the same spot, but new movement elsewhere on the wall is a separate issue we'd assess on its own.
We recommend waiting for the injection material to fully cure, typically 24 to 48 hours, before painting or finishing the area.
Interior injection can often be done without removing drywall, since the injection ports only need access to the crack line itself, not the full wall surface.