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Interior and Exterior City Subsidy Paperwork Handled

Basement Waterproofing in Toronto

Renovator Toronto waterproofs Toronto basements from the inside and the outside. Interior drainage systems run $80 to $150 per linear foot and exterior excavation $150 to $300, and the City of Toronto pays 80 percent of eligible flood protection costs up to $6,650 per property. We do the work and hand you the invoice in the form the subsidy application asks for.

Interior drainage $80 to $150 per linear foot
Exterior excavation $150 to $300 per linear foot
City subsidy covers up to $6,650 per property

Get a waterproofing estimate

Tell us where water appears, how often, and whether you already have a backwater valve or sump.

What can we help with?

So the right crew reviews your project.

We diagnose the water path before quoting a system. HST at 13 percent shown.

Why Toronto basements are getting wetter

The storms have grown

The City's own reporting puts annual precipitation at about 795 mm for 1971 to 2000, rising to 840 mm by 2015, with the wettest day of the year up from 37 mm to 41 mm. Extreme 24-hour storms are projected 27 to 51 percent higher by late century.

It is already happening

Heavy rain in July and August 2024 caused basement and surface flooding at more than a thousand Toronto properties. The City has run basement flooding environmental assessment studies in 67 separate areas.

Freeze-thaw opens the path

Toronto averages about 65 freeze-thaw cycles and 134 days at or below freezing a year. Every cycle widens a parging crack or a joint a little, which is why a wall that held for twenty years stops holding.

Interior or exterior

Which system your basement needs, and why the price gap is so wide

Interior waterproofing means breaking the slab perimeter, installing new weeping tile and drainage stone inside the footing, running it to a sump, and sealing the wall from within. It runs $80 to $150 per linear foot, a full interior system typically $8,000 to $15,000, and it works without touching your landscaping, driveway or deck. Exterior waterproofing means excavating to the footing from outside, cleaning and membraning the wall, and installing new drainage against it. It runs $150 to $300 per linear foot, a single wall $5,000 to $12,000 and a full perimeter $15,000 to $35,000. Exterior is the more complete fix because it stops water at the wall rather than managing it once it is inside, but it is priced against whatever is on top of that ground. Where a basement is being underpinned anyway, the exterior premium largely disappears, because the wall is already open.

$6,650 City subsidy cap per property, from 1 May 2026
80% Share of eligible invoiced cost the subsidy covers
1,000+ Toronto properties flooded in July and August 2024
41 mm Toronto wettest day of the year by 2015, up from 37 mm

Basement waterproofing measures, usually combined

Six measures, usually combined rather than chosen one at a time.

$80 to $150 per linear ft

Interior drainage system

Slab perimeter opened, new weeping tile and stone inside the footing, run to a sump, wall sealed from within.

$150 to $300 per linear ft

Exterior excavation and membrane

Wall excavated to the footing, cleaned, membraned and drained. Single wall $5,000 to $12,000, full perimeter $15,000 to $35,000.

$650 to $4,000

Sump pump and battery backup

Sump pit and pump sized to the lot, with a battery backup so it still runs when the storm takes the power.

$2,000 to $4,500

Backwater valve

A valve that stops sewer backflow reaching your basement. Subsidy-eligible to $1,600 each for up to two devices.

$450 to $1,100 per crack

Crack injection

Poured-wall cracks injected from inside where the wall is otherwise sound and the crack is the whole problem.

Cheapest fix first

Grading and downspouts

Downspouts discharging away from the wall and grade sloped away from the foundation, which is often the actual cause.

How we diagnose before we sell a system

A waterproofing quote written without these four checks is a guess with a price on it.

Where the water appears, and when

Water at the floor-wall joint after heavy rain points at the footing and the foundation drain. Water down a wall points at grade, a downspout or a crack. Water backing up a floor drain points at the sewer and a missing backwater valve. Three different problems, three different systems.

Whether the foundation drain still exists

On older Toronto houses a foundation drain was often severed from the sewer decades ago, so water reaches the footing with nowhere to go. Severing and capping is itself a subsidy-eligible item at up to $400.

The cheap causes, before the expensive ones

Downspouts discharging at the wall and grade sloping toward the house cause a meaningful share of what gets diagnosed as a foundation problem. We check those first and will tell you when that is the whole job.

Your subsidy eligibility

The application needs work done by a licensed contractor, filing within two years of installation, downspout disconnection compliance and no outstanding City debts. We confirm those before quoting so the rebate is not lost on a technicality.

Basement waterproofing rates per linear foot

Published Toronto ranges current in 2026. A second guide from the same publisher gives interior at $70 to $230 per linear foot, which we note rather than hide. Figures are before HST at 13 percent.

Most popular

Interior Drainage

$80 – $150 / linear ft

  • Full interior system: $8,000 – $15,000
  • No disturbance to landscaping or driveway
  • Manages water once it reaches the footing
Get a written quote

Exterior Excavation

$150 – $300 / linear ft

  • Single wall: $5,000 – $12,000
  • Full perimeter: $15,000 – $35,000
  • Stops water at the wall rather than managing it inside
Get a written quote

Sump Pump

$650 – $4,000

  • Subsidy covers up to $2,250
  • Battery backup covered to $300
  • Sized to the lot, not to a catalogue
Get a written quote

Backwater Valve

$2,000 – $4,500

  • Subsidy covers up to $1,600 each, two devices
  • Stops sewer backflow into the basement
  • Permit for the work runs about $200 – $800
Get a written quote

Crack Injection

$450 – $1,100 / crack

  • For sound poured walls with a single leak path
  • Not a substitute for drainage where the footing is the issue
  • Quickest of the measures to complete
Get a written quote
Our Process

How a waterproofing job runs

1

Diagnose the water path

Where water appears and when, foundation drain condition, grade, downspouts, floor drain and whether a valve exists.

2

Scope, subsidy check and quote

Interior against exterior priced on what the diagnosis found, with your subsidy eligibility confirmed before you commit.

3

Install

Slab or excavation work, new drainage, sump, valve and sealing, with any required permit filed and inspection booked.

4

Restore, test and document

Slab or grade restored, the system tested, and the invoice issued in the form the City subsidy application requires.

Basement waterproofing reviews from Toronto owners

5/5

The crew completed our basement renovation with excellent attention to detail. They listened to our needs, offered practical suggestions, and created a comfortable space for our family.

Daniel P.

Direct Client

Direct Client

5/5

We had a great experience with the team from the initial estimate to the final walkthrough. Communication was clear, the schedule was well managed, and the results look fantastic.

Christopher T.

Direct Client

Direct Client

5/5

We hired the team for a bathroom renovation in our Toronto home. They handled the demolition, tile work, and finishing details professionally and kept the work area organized.

Jennifer R.

Direct Client

Direct Client

Waterproofing questions from Toronto owners

How much does basement waterproofing cost in Toronto?

Interior drainage runs $80 to $150 per linear foot with a full interior system typically $8,000 to $15,000. Exterior excavation runs $150 to $300 per linear foot, a single wall $5,000 to $12,000 and a full perimeter $15,000 to $35,000. A sump pump is $650 to $4,000 and a backwater valve $2,000 to $4,500.

How much will the City pay toward it?

Eighty percent of eligible invoiced costs to a total of $6,650 per property as of 1 May 2026. Within that, a backwater valve is covered to $1,600 each for up to two devices, a sump pump to $2,250, a battery backup to $300, foundation drain severance and capping to $400 and a plumbing assessment to $500.

Is interior or exterior waterproofing better?

Exterior is the more complete fix because it stops water at the wall, but it costs roughly double per linear foot and disturbs whatever sits on that ground. Interior is less invasive and manages water once it reaches the footing. Which one is right depends on where your water is arriving, which is what the diagnosis establishes.

Do I need a permit to waterproof a basement?

The waterproofing itself often does not, but the plumbing work usually does. Contractor guides put Toronto waterproofing permits at about $200 to $800 and backwater valve work in the same band. We confirm the requirement for your specific scope and file it where it applies.

Stop the water before you finish the basement

Book a diagnosis. We find the path first, then price the system that addresses it.

Request a Free Estimate Call (365) 360-7014
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