Foundation Crack Repair in Scarborough, Toronto

Coverage: We service Toronto, the GTA and Southern Ontario, and Scarborough is home ground — east-end routes run daily, travel folded into the flat pricing. The assessment is free, and most Scarborough cracks are injected in the same visit.

The Scarborough Bluffs are a 15-kilometre cross-section through everything under this district, rising to roughly 110 metres above Lake Ontario at their highest. Reading TRCA’s stratigraphy from the bottom up: the Scarborough Formation, whose lower half is fine silt and clay and whose upper part is sand; the Sunnybrook Drift, “a cohesive silty clay” that restricts downward groundwater flow; the Thorncliffe Formation, which “contains layers of riverine sands interbedded with fine-grained glacial tills”; and at surface the Leaside and Halton Tills — sandy silt tills — with Lake Iroquois Sand present “in place of or overlying the tills in several areas.”

That last unit is the one under a great many Scarborough basements. Glacial Lake Iroquois stood about 60 metres higher than today’s lake, and Parks Canada places its old shoreline 4 to 15 kilometres inland, “passing through areas that are now the Toronto Zoo, and the former Beare Road landfill site.” Where you sit relative to that line changes your basement’s failure mode. On the Iroquois sand, water moves freely and arrives at the wall fast — free-draining ground, but any crack sees pressure quickly. On the tills, which are low-permeability, water perches in the backfill zone instead of soaking away, and the wall carries the load. TRCA’s own observation that groundwater “moves readily through the sands, but more slowly through the lower permeability tills” is the whole story in one sentence, and it is why two houses three streets apart behave nothing alike.

Then there is the watershed. Highland Creek drains about 102 square kilometres and TRCA calls it “the most urbanized watershed in the Toronto region” — just 6% forested, only 11.4% of the landscape still natural cover, and roughly 9% of it served by stormwater management controls. Water that lands on Scarborough has very little ground left to soak into, so it moves fast and it arrives all at once. The Rouge to the east is a different animal at roughly 339 square kilometres and about 26% natural, anchored by the 79-square-kilometre Rouge National Urban Park established in 2015.

The increase was real and worth claiming: the combined cap went from $3,400 to $6,650, backwater valve and sump pump amounts rose 28%, a second valve became eligible for homes with multiple sewer connections, and the application window doubled from one year to two. The program has paid roughly $85.6 million across 59,173 applications since 2007, reaching about 14% of Toronto’s residential properties.

What it will not do is fix your wall. And the City is not shy about whose job that is — its own prevention page tells homeowners to “seal cracks or leaks in walls, floors, windows, window wells and your home’s foundation,” and states that “homeowners are responsible for plumbing from the property line to inside the home.” We are injection specialists, not plumbers: the subsidy measures belong to a licensed plumbing or drain contractor holding a City business licence, and note that a backwater valve installation does require a building permit even though your crack repair does not. Where your flood plan pairs a wall repair with subsidised drainage work, we time our visit around it and hand you a documented, itemised record for the wall side of the file.

Toronto ran Environmental Assessments across 67 basement flooding study areas between 2006 and 2024. Twelve of them are in Scarborough: Victoria Park from Eglinton to Steeles (2008), Warden and Finch East (2011), Clairlea–Birchmount (2018), Scarborough Waterfront (2021), Steeles East and Port Union (2022), Rouge River South and North, Agincourt–Highland Creek West and East (all 2023), and South Scarborough–Highland Creek, West and East (2024). The clustering on Highland Creek is not a coincidence — it is the most urbanized watershed in the region, with the least ground left to absorb anything.

Here is the part worth being straight about. That $2 billion capital program addresses infrastructure “within the City’s right-of-way and public property like parks and ravines” — explicitly not private property. Being inside a study area tells you the City has identified a surcharge risk on your street. It does not mean anyone is coming to look at your wall, and it does not entitle you to anything beyond the subsidy above. What it does tell you honestly is that if your basement takes water only during heavy storms, the cause may sit in the sewer rather than in your foundation — and we would rather say that at a free assessment than sell you an injection that fixes nothing.

A crack that runs during and after heavy rain — the signature of free-draining Iroquois sand delivering water straight to the wall — gets hydrophobic polyurethane ($750–$1,000). It cures against live water and stays flexible. A crack that has grown across seasons, or one carrying structural load, gets epoxy injection that re-bonds the wall ($850–$1,500). Tie-rod leaks run $75–$150, extra cracks are 5% off each, and the complete method guide, the polyurethane page, the epoxy page and the open price sheet hold nothing back. Not sure which pattern you are looking at? Our guide to the five types of foundation crack explains what each orientation indicates, and why width alone tells you very little.

Scarborough Township was established in 1850 with a population of about 3,000. It stayed that way for a century. Then, in the City of Toronto Archives’ own words, “between 1950 and 1955, its population doubled from 48,000 to 110,000, tripling again between 1955 and 1970.” Highway 401 opened through it in 1956 and the farms went under subdivisions of single-family homes almost overnight.

The census still shows it. Of 218,920 private dwellings in the Scarborough Community Council area at the 2021 census, 48,370 date from 1960 or earlier and 80,740 from 1961 to 1980 — 129,110 homes, 59% of the district, built in 1980 or before. Poured foundation walls from that era are now 45 to 75 years old, sitting in ground that has been urbanising around them the whole time. That is the single most useful thing to know about foundations here, and it is why we see the same three or four crack patterns across whole streets.

Photo quotes come back the same day; the on-site assessment is free either way. A typical crack takes 60–90 minutes from the basement side — no excavation through Scarborough landscaping, no seasonal blackout. On permits, Toronto is unusually clear and it works in your favour: the City’s published list of work that does not require a building permit includes “undertaking waterproofing repairs to a basement.” Interior crack injection is a waterproofing repair with no structural alteration, no excavation, no underpinning and no plumbing work. What does require a permit is structural or material alteration, excavating or constructing foundations, basement underpinning, a basement entrance, and — worth knowing if you are also claiming the subsidy — installing a backwater valve. Questions go to 311 within Toronto, or 416-392-2489 from outside the city.

Walls in the Iroquois sand belt can need patient multi-port injection because water keeps arriving during the work. Long full-height cracks use more resin than hairlines. Finished basements — common in a district of 1960s and 70s homes that have been renovated twice — add access care. Block foundations, which do turn up in the older stock, are a different conversation: injection is engineered for poured concrete, where a crack is a discrete plane through a monolithic pour, and mortared block has no such plane for resin to seal against. We tell you that at the assessment rather than inject a wall that will not hold it. Every crack after the first is 5% off, and all of it is on the published cost breakdown before we ever ring your doorbell.

Birch Cliff, Cliffside, Cliffcrest, Guildwood, West Hill, Highland Creek, Rouge, Malvern, Agincourt, L’Amoreaux, Wexford, Dorset Park, Bendale, Woburn, Eglinton East, Ionview, Kennedy Park, Scarborough Village, Morningside, Centennial, Milliken and Steeles. Rather than guess at build decades street by street, the honest frame is the district one: 59% of Scarborough’s housing predates 1981, and the great bulk of it went up in the two decades after Highway 401 opened in 1956. Our Markham guide covers the next municipality north, our Oshawa guide the Durham lakeshore east, and the full service-area index lists every city we publish for.