How Much Does Basement Waterproofing Cost in Toronto in 2026?

WaterproofingIndex compiled this table from 9 named Canadian sources; where they disagreed, we widened the range rather than pick one.

Not every quote is the same job. These are the variables that move basement waterproofing pricing most in Toronto, so you can read a quote and see where the money goes.

• Interior versus exterior method. This is the largest single swing in the quote: roughly $50 to $180 per linear foot interior against $150 to $475 per linear foot exterior across the GTA sources here.
• Foundation depth. OCM Excavation digs to the bottom of the footing, 7 to 9 feet on most GTA homes, and prices a 7-foot basement at $250 to $400 per linear foot against $300 to $475 for an 8-foot one.
• How many walls you do. A single 30-foot wall runs $8,500 to $13,500 all in (OCM), while wrapping all four walls of an average detached runs $25,000 to $55,000. Most homeowners with one wet corner only dig that corner.
• Perimeter length. Project Landscaping notes most Ontario homes have foundation perimeters between 100 and 150 linear feet, which is what turns a per linear foot rate into a project total.
• Site access. OCM notes that Old Toronto lots with 4-foot side yards cannot fit a mini excavator, and that decks, air conditioner units and gas meters have to come out and go back. Both add labour to an exterior dig.
• Whether the weeping tile is being replaced or just protected. OCM prices new 4-inch perforated PVC weeping tile at $90 to $140 per linear foot inside the exterior scope, so a job that reuses sound drainage costs less.
• Whether a sump pit is needed. A pit and pump adds $2,500 to $4,500 to an exterior job (OCM) when the foundation drain has to be severed off the sanitary sewer, versus $2,200 to $3,000 for a standalone sump pump installation (Rock Basements).
• Interior system tier. Project Landscaping separates basic interior drainage at $50 to $80 per linear foot from a full perimeter system with membrane at $70 to $120 and a premium system with backup pump at $100 to $180.
• Underpinned or benched basements. OCM notes that excavating below an underpinning bench needs engineered shoring, which is an added engineering and shoring cost rather than a per linear foot one.
• Restoration scope. OCM restores grade and rough topsoil but quotes final sod, interlock reset and plantings separately, so compare quotes on whether landscaping is in or out.

Ontario rules and Toronto's climate change the math in ways national price guides miss. Here is what applies locally, from HST to permits to freeze-thaw.

• HST: Ontario charges 13% HST and residential waterproofing contracts are taxable. Almost every per linear foot figure published by GTA contractors is quoted before tax, so a $25,000 exterior job is about $28,250 out the door. The City of Toronto's own subsidy page confirms taxes are part of the invoiced cost it reimburses against.
• City of Toronto Basement Flooding Protection Subsidy Program: as of May 1, 2026, the City offers up to $6,650 in subsidies per property. The expanded amounts apply to eligible work completed on or after November 12, 2025. Eligibility is limited to owners of a single-family, duplex, triplex or fourplex residential home, and applications are online.
• The individual subsidy caps published by the City are: up to 80 per cent of the invoiced cost to a maximum of $500 for a one-time home plumbing assessment; a maximum of $1,600 per backwater valve for up to two devices; a maximum of $2,250 for a sump pump, with an additional $300 for a battery backup; and a maximum of $400 for severing and capping a foundation drain (weeping tile) connection to the City sewer.
• The subsidy does not cover the waterproofing itself. Excavation, membrane and weeping tile are not on the City's eligible work list. Only the plumbing assessment, backwater valve, sump pump and battery backup, and the foundation drain severance qualify. Disconnecting downspouts from your eavestrough is explicitly not eligible for a subsidy.
• Subsidy administration to plan around: properties have a lifetime maximum for each type of eligible work, subsidies are issued first come first served subject to annual funding approved by City Council, submitting an application does not guarantee a subsidy, and the City says it can take up to 10 weeks to receive payment. Homeowners can check their property's subsidy history with the City before assuming a cap is still available.
• Licensing matters for the rebate: the City requires a licensed plumber to complete the Home Plumbing Assessment Form, and states that different types of contractors are licensed to perform different types of eligible work. Confirm your contractor holds the right licence before the work is done, not after.
• If a sump pump and a battery backup are both installed, the City requires the contractor to itemize the cost of each component separately on the invoice, or the backup subsidy cannot be assessed.
• Digging next to a foundation in Ontario carries statutory obligations. OCM Excavation's process notes locating utilities through Ontario One Call and hand-exposing gas and hydro within 1 metre of the wall, then excavating with a safe slope or shoring per OHSA. A quote that skips locates and shoring is not a cheaper quote, it is an unsafe one.
• OCM states that a weeping tile currently discharging to the sanitary sewer is illegal under Toronto's bylaw, and that correcting it means adding a sump pit and pump at $2,500 to $4,500. That correction is also the work the City's $400 foundation drain severance subsidy is aimed at.
• Published warranty terms in this market, quoted only where the company publishes them: Aquatech Waterproofing states it offers a lifetime warranty and that exterior waterproofing can last 25 or more years. DryShield advertises a lifetime transferable warranty. OCM Excavation says every job comes with a written workmanship warranty but does not publish a term. Nusite notes interior weeping tile systems last 15 to 20 years. Get the term, the transferability and the exclusions in writing before you sign.
• Season and soil: Toronto homes built before 1980 often sit on original tar coating and clay weeping tile, which is the failure OCM says drives most exterior digs in East York, Etobicoke and Scarborough. Exterior work needs open ground, so it is a spring to late-fall job in the GTA.

You can keep basement waterproofing costs down without cutting the parts that matter. These are the levers GTA homeowners actually use, each tied to a real number above.

• Fix the crack before you buy the system. Professional injection is $300 to $800 per crack (Nusite). If one crack in a sound wall is the whole problem, that is a fraction of a $15,000 to $35,000 perimeter job. Insist a contractor shows you why a spot fix will not hold before upselling you.
• Do one wall, not four. OCM prices a single 30-foot wall at $8,500 to $13,500 all in against $25,000 to $55,000 for a full four-wall wrap. Water usually enters on one elevation, so pay for that elevation.
• Claim the City of Toronto subsidy on the parts that qualify. The sump pump (up to $2,250), battery backup (up to $300), backwater valves (up to $1,600 each, two maximum) and foundation drain severance (up to $400) can recover a meaningful share of a $2,200 to $4,500 pump and valve package, up to the $6,650 property maximum.
• Bundle the subsidized items into the excavation you are already paying for. The pit, pump and valve go in while the ground is already open and the drains are already exposed, which is cheaper than a separate mobilization later, and the invoice still supports the rebate claim.
• Compare exterior quotes on dig depth, not on the headline rate. A $250 per linear foot quote and a $475 one can both be honest if one is a 7-foot basement and the other is an 8-foot one. Ask for depth, membrane spec and whether new weeping tile at $90 to $140 per linear foot is included.
• Consider interior if the wall itself is sound. A full interior perimeter system with membrane is $70 to $120 per linear foot (Project Landscaping) against $150 to $475 per linear foot for exterior. On a finished basement with a structurally fine wall, interior is a legitimately cheaper answer, not a lesser one.
• Skip the premium interior tier unless you need it. Basic interior drainage is $50 to $80 per linear foot versus $100 to $180 for a premium system with backup pump. Buy the backup pump only if a power failure during a storm would actually flood you.
• Get the whole-project total, not just the rate. Ask every contractor to multiply their per linear foot rate by your actual perimeter, which Project Landscaping notes is typically 100 to 150 linear feet on an Ontario home, and to state the total before HST and after.
• Take the plumbing assessment subsidy first. The City reimburses up to 80 per cent of a one-time home plumbing assessment to a maximum of $500, and you are not required to implement any of the plumber's recommendations to keep the subsidy. It is a cheap second opinion before you commit to a five-figure job.
• Check your property's subsidy history before you budget for it. Each type of eligible work has a lifetime maximum per property, so a previous owner may have already used part of the $6,650. The City will tell you what is left.
• Get the warranty in writing and check whether it transfers. Aquatech and DryShield both advertise lifetime terms, and OCM provides a written workmanship warranty. A transferable warranty is worth real money at resale, and it costs nothing extra to ask for the document up front.

Every price on this page comes from a named Canadian source, and where sources disagreed we widened the range rather than pick a favourite. Here is how WaterproofingIndex reconciled the numbers.

• Every figure in this guide was read off a live Canadian page before it was published. Where a source gave a range but no average, the typical column is the midpoint of that same source's range, rounded. No two sources were ever blended into a new number.
• Interior and exterior are two different products at two different prices, and that is the single biggest fork in any quote. GTA interior drainage runs roughly $50 to $180 per linear foot depending on tier (Project Landscaping), while exterior excavation and membrane runs $150 to $475 per linear foot (Nusite at the low end, OCM Excavation at the high end). Interior manages water that has already reached the wall. Exterior stops it at the wall.
• Exterior per linear foot pricing disagrees sharply between GTA contractors, and the gap is real rather than a typo. Nusite publishes $150 to $300 per linear foot for the Greater Toronto Area. OCM Excavation, an excavation specialist, publishes $250 to $400 for a 7-foot basement and $300 to $475 for an 8-foot basement. Read any exterior quote for dig depth before you compare it to another one.
• Whole-house exterior totals split the same way. Nusite puts a complete perimeter at $15,000 to $35,000. OCM puts a full four-wall wrap on an average detached at $25,000 to $55,000. Both are GTA 2026 figures, so treat $15,000 as a floor for a shallow, easy-access foundation and $55,000 as a deep or awkward one.
• Depth is the multiplier on exterior work, not square footage. OCM prices the same wall at $250 to $400 per linear foot at 7 feet and $300 to $475 at 8 feet, so a bungalow with a deeper basement can cost meaningfully more per foot before anyone touches the membrane spec.
• Rebate figures published by contractors go stale fast. Rock Basements' calculator still shows up to $1,750 for a sump pump and up to $1,250 for a backwater valve. Those are the City of Toronto amounts for work completed before November 12, 2025. The City's own page now lists higher expanded amounts. Always price the rebate off the City page, never off a contractor's page.
• Sump pumps are quoted very differently depending on whether the pit already exists. Rock Basements lists a straight sump pump installation at $2,200 to $3,000. OCM lists $2,500 to $4,500 when a new pit has to be dug and the weeping tile severed off the sanitary sewer as part of an exterior job.
• A crack is not always a system problem. Nusite prices professional injection at $300 to $800 per crack, a small fraction of the $15,000 to $35,000 it prices a full perimeter exterior job at. A single leaking crack in an otherwise sound wall is worth injecting before anyone sells you an excavation.
• US cost guides were excluded from this guide entirely. Every price row comes from a Canadian company publishing CAD figures for Ontario or the GTA specifically.
• The HomeStars Toronto basement waterproofing price guide was attempted as a source but returned an HTTP 403 to automated requests, so nothing from it was used.

Sources

• OCM Excavation & Construction - Basement Waterproofing Excavation Cost Toronto: 2026 Guide (May 2026)
• Nusite Group (Toronto) - How Much Does Waterproofing Cost in Toronto?
• Project Landscaping - Cost of Basement Waterproofing in Ontario 2026 (price calculator and depth breakdown)
• DryShield - Toronto Basement Sealing & Waterproofing Cost Guide 2026
• Rock Basements - Basement Waterproofing Cost Calculator (GTA average costs table)
• Aquatech Waterproofing (Toronto) - How Much Does Basement Waterproofing Cost? (updated January 2026)
• RCC Waterproofing - Service Pricing Guide (Toronto)
• AquaMaster Plumbing - Basement Waterproofing Cost in Toronto, Ontario 2026
• City of Toronto - Basement Flooding Protection Subsidy Program

WaterproofingIndex tracks 225 basement waterproofing contractors across the Greater Toronto Area, rated 4.84★ on average. The three below rank highest on our review-weighted score, based on WaterproofingIndex's analysis of 225 GTA businesses, August 2026.

• 1

  Aquatech Basement Waterproofing Toronto

  5.0(821 Google reviews)

  0.8 km from York centre

  YorkBasement Waterproofing

  Its own website describes below-grade water work

  (416) 300-2191Call
• 2

  Royal Work Basement Waterproofing Toronto

  5.0(452 Google reviews)

  0.2 km from Harbourfront centre

  HarbourfrontBasement Waterproofing

  Its own website describes below-grade water work

  (416) 837-1077Call
• 3

  Canada Waterproofers

  5.0(325 Google reviews)

  2.5 km from Mississauga centre

  MississaugaBasement Waterproofing

  Its own website describes below-grade water work

  (905) 270-5325Call

The table above is the market. These calculators put your own basement into it, and they add the HST and any City of Toronto subsidy that applies.

• Price your own wall length and basement depth
• Interior against exterior, with the lifespans divided in
• Work out where the water is actually getting in