Foundation Waterproofing in North York

OCM Excavation & Construction has been digging foundations, cutting drain tile and rebuilding wet basements across North York since 2008. We work the full former-North-York footprint — Don Mills, Willowdale, Bayview Village, Hoggs Hollow, Lawrence Park, Bedford Park, Wilson Heights, North York Centre and Newtonbrook. If your basement is leaking, your weeping tile has collapsed, or your 1950s tar coating has finally aged out, call us at 416-317-3090 for an on-site assessment. Most North York jobs we quote in person within 48 hours.

Why foundation waterproofing in North York is different

North York is not one neighbourhood — it is half a dozen housing stocks built across seventy years, and every one of them fails differently.

• Don Mills (1950s planned community) — The original Macklin Hancock build is now about 70 years old. Original-spec tar waterproofing was rated for 20-30 years. We routinely dig Don Mills foundations and find the membrane is gone, the parging has spalled, and the clay drain tile is silted shut. Full perimeter excavation is the norm here, not the exception.
• Bayview Village & Hoggs Hollow — Luxury heritage stock, big lots, deep basements, often with finished interiors that owners do not want disturbed. Exterior excavation makes sense even when interior work would be cheaper, because we avoid touching the finished side. Hoggs Hollow also sits in the West Don ravine system — TRCA permits apply for any work near the regulated slope.
• Willowdale infill — Tight side-yard access between teardowns and surviving 1960s bungalows. We hand-dig or use a mini-ex on a 4-ft side yard more often in Willowdale than anywhere else in the GTA.
• Lawrence Park & Bedford Park — Estate lots, large mature canopy. Toronto Chapter 813 protects any tree at 30 cm DBH or larger on private property, with fines from $500 up to $100,000 per tree for unpermitted damage. If a 60 cm maple sits inside your dig zone, we hand-dig the tree-protection zone, root-prune cleanly and document it.
• Don Mills, Newtonbrook, Bayview corridor — Many properties drain into the Don Valley or its tributaries. TRCA Ontario Regulation 41/24 applies if you are within the regulated area.
• City of Toronto Basement Flooding Protection Subsidy — North York is part of the City of Toronto (amalgamated 1998), so the subsidy program applies. Up to $6,650 total per property for work completed on or after Nov 12, 2025: backwater valves up to $1,600 each (max two), sump pump up to $2,250, battery backup up to $300, foundation drain severance/capping up to $400, plumbing assessment up to $500. Reimburses 80% of invoice per component. Confirm your eligibility with 311 before you start.

Types of waterproofing we do in North York

• Exterior excavation (the real fix) — Dig to footing, scrape and pressure-wash the wall, parge any cracks or bad joints, apply a modern rubberized membrane or dimpled drainage board, replace the weeping tile with perforated PVC in clear stone wrapped in filter cloth, tie into the sump or storm. This is what we recommend for the Don Mills 1950s stock and any Bayview Village heritage home where the original tar is gone.
• Interior waterproofing — When exterior excavation is not practical (zero-lot-line, finished landscaping the owner will not touch, neighbour-side wall) we cut the slab inside, install an interior weeper bed and a dimple membrane up the wall to a discharge pit.
• Drainage retrofits & weeping tile replacement — If the wall itself is sound but the tile is failing, we replace the tile only. Different scope, different price than full waterproofing.
• Sump pits and pumps — New pit, primary pump, battery backup — sized to your roof area, lot grading and water table.
• Crack injection — Polyurethane or epoxy for isolated poured-concrete cracks when the rest of the wall is dry.

Our waterproofing process

1. On-site assessment — We look at the wet spot, the grade, the downspouts, the age of the house and the access to your North York lot. No phone quotes for waterproofing.
2. Scope & permits — Toronto Building permit if structural, Chapter 813 tree permit if a protected tree is in the dig zone, TRCA clearance if you are in a regulated area near the Don.
3. Locate & protect — Ontario One Call, tree-protection fencing, dust control for the interior, plywood over your walkways.
4. Excavate — Mini-ex where access allows, hand-dig inside any tree-protection zone or within 1 m of the wall.
5. Wall prep & membrane — Clean, parge, primer, membrane, drainage board.
6. Drain tile & backfill — New tile, clear stone, filter cloth, granular backfill in lifts, topsoil and grade restoration.
7. Final grade — Pitched away from the wall at the slope your warranty needs.

What affects waterproofing cost in North York

• House age and wall type — Don Mills 1950s block-and-parge takes more prep than a Newtonbrook 1970s poured wall. Hoggs Hollow stone foundations take more again.
• Basement depth — 7-ft basements run $250–$400/linear foot for full exterior waterproofing, 8-ft runs $300–$475/ft, 9-ft (often with underpinning) runs $400–$650/ft. Weeping tile replacement only, without new membrane, runs $90–$140/ft.
• Tree protection — A protected tree (30 cm DBH or larger under Chapter 813) inside the dig zone means hand-dig, root pruning by a certified arborist, and permit paperwork. Add days and cost.
• TRCA regulated area — Hoggs Hollow, parts of Don Mills near the Don, anywhere on the ravine edge. Adds permit time before we can break ground.
• Access — A Willowdale infill with 4 ft of side yard between two new builds is hand-dig only. Narrow side-yard premium runs +$50–$100/ft on our exterior scope.
• Restoration — Sod, interlock, garden re-build, irrigation re-tie. Estate-lot Lawrence Park restoration is often 20% of total project cost.

For full GTA-wide context on our waterproofing scope, see our foundation waterproofing Toronto & GTA page. For related dig work in this area, see excavation contractor North York and trenching in North York.

FAQ — foundation waterproofing in North York

My Don Mills basement leaks only when it rains hard — do I really need to excavate?

Probably yes. On a 1950s Don Mills build the original tar membrane is past its service life and the clay drain tile is usually silted up. Interior systems can manage water once it gets in, but exterior excavation is the only way to actually stop it at the wall. We will tell you on-site which makes sense for your specific house.

Will I qualify for the Toronto Basement Flooding subsidy?

North York is part of the City of Toronto so the program applies. Up to $6,650 per property total, covering 80% of invoiced cost for backwater valves (max $1,600 each, up to two), sump pump ($2,250), battery backup ($300), foundation drain severance ($400) and a plumbing assessment ($500). Apply within two years of install. Confirm current eligibility with 311.

There is a mature maple over my dig zone in Lawrence Park — can you still excavate?

Yes, but carefully. Toronto Chapter 813 protects any private tree at 30 cm DBH or larger, with fines from $500 to $100,000 per tree for unpermitted damage. We hand-dig the tree-protection zone, use an arborist for clean root pruning where unavoidable, and document the work. Plan an extra week or two for the Chapter 813 permit.

How long does a full perimeter waterproofing job take on a typical North York house?

Depends on lot access and weather. A standard 8-ft basement on a Willowdale or Newtonbrook lot with mini-ex access runs 5–10 working days for the dig, membrane, drain tile and backfill. Add days for tree-protection hand-dig, narrow side-yard access, or restoration like interlock and sod.

If your North York basement is wet or you are planning ahead before you finish the downstairs, call OCM at 416-317-3090. We will come look at it.

Related Services in North York

• Foundation Waterproofing in Burlington
• Foundation Waterproofing in Newmarke
• Foundation Waterproofing in Vaughan
• Foundation Waterproofing in Toronto
• Drainage & French Drain in Vaughan
• French Drain Installation in Auror
• Sump Pump Installation in North York
• Basement Underpinning in North York
• Window Well Installation in North York
• Egress Window Installation in North York