Basement and foundation leaks stopped permanently from the inside — no digging, no landscaping torn up.
Specialty Grouting Services repairs leaking foundations for homeowners, home builders, high-rise developers, and property managers across Ontario. The same injection grouting we use to seal municipal tanks and tunnels works in a basement: we drill to the leak path and inject a water-activated resin that follows the water, expands, and seals the crack through the full thickness of the wall.
How do you fix a leaking foundation crack without excavating?
From inside the basement. Injection ports are set along the crack, and a water-activated flexible polyurethane resin is injected under controlled pressure. The resin reacts with the water in the crack, expands to fill it from the inside face to the outside soil, and cures into a flexible, permanent seal that moves with the wall through seasonal cycles. Where cracks are wide or numerous we first parge them with quick-setting cement to contain the injection. Pipe and conduit penetrations — the wiring, gas, and water services that were never sealed when the house was built — are plugged with the same water-swelling materials.
Where do basement foundation walls usually leak?
- Vertical cracks beside windows — where the wall steps down for a window well the concrete is stressed, and cracks commonly form at those corners.
- Full-height shrinkage cracks in poured concrete walls, often first noticed as a damp line or a stain on finished drywall.
- Service penetrations — wiring, conduit, and pipe entries through the foundation that were never properly sealed.
- Stairwells and walkouts — water from a garden or walkway finding the wall and running under a door into the finished space.
- Block foundation walls — mortar joints and hollow cores that take on water from saturated soil.
Can a leak be repaired in winter or during a renovation?
Yes. Injection works year-round as long as the concrete is warm enough for the resin to react properly; in extreme cold we heat the basement before the work. For renovations we coordinate with the builder so the wall is opened, repaired, tested, and closed back in on schedule.
Recent foundation leak repairs
Basement foundation leak — finished basement
Leaking cracks at several locations in a poured concrete foundation wall had damaged the interior wall and floor finishes and caused mould in the stud wall cavity, drywall, and carpet. The wallboard and mouldy materials were removed, the cracks were located and injected, and the wall was rebuilt and finished so no sign of the repair remained.
Stairwell foundation leak
Water from the front garden was leaking through the foundation wall into a stairwell and under the door into a finished basement, damaging the flooring. The wall was drilled and injected with a water-activated flexible resin to seal the crack, then the garden was flooded to prove the repair before the basement was closed back in.
Basement renovation in extreme cold
A renovation scheduled through the coldest weeks of winter had severe wall cracks at six locations. The basement was heated to bring the concrete up to temperature so injection would be effective, and because the cracks were wide open they were parged with quick-setting cement to contain the resin. The repairs were complete in three days and the renovation proceeded on schedule.
Furnace room pipe penetration
Water had been running across a furnace room floor to the drain for years from equipment wiring that passed through the foundation without a proper seal, leaving rust stains and an unusable room. Water-swelling pipe plugging material was injected between the wiring and its PVC conduits, and the leaks stopped.
Frequently Asked Questions
It depends on the number and length of the cracks, whether finishes have to be removed and reinstated, and access. Send photos to bill@sgservices.ca or call 226-820-4233 for a price — most single-crack repairs can be quoted from photos.
Yes. The flexible polyurethane resin fills the crack through the full wall thickness and stays flexible, so it keeps sealing as the wall moves with the seasons. The stairwell repair above was tested by flooding the garden before we left.
No. Injection repairs are completed from inside the basement, which is why they can be done year-round without disturbing landscaping, driveways, or decks.
Yes. We repair foundation leaks for home builders, high-rise developers, and property managers — including parking garage and foundation leaks in commercial and multi-residential buildings — and for individual homeowners.
Clear access to the wall where the leak is. If the wall is finished, we will discuss whether the drywall needs to come off and who reinstates it, so there are no surprises on the day.
MunicipalSanitary Manhole Leak Repairs — City of WaterlooActive groundwater inflows through joints and pipe penetrations in three sanitary manholes sealed by polyurethane injection — without taking the sewer out of service.Read the case study
MunicipalManhole Leak Repairs — Tavistock Community CentreInfiltration through pipe penetrations in a precast manhole stopped with water-activated resin, keeping fines out of the sewer and the structure in service.Read the case study
Rail & TransitTransit Tunnel Joint Sealing & Backwall Grouting — CalgaryLeaking joints in a light rail tunnel sealed and voids behind the liner filled at track level during overnight possessions, without disrupting service.Read the case studyWater Coming Through Your Foundation?
Send us a few photos of the leak and we’ll tell you what it will take to stop it for good.