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WaterproofingIndex

Basement Waterproofing Contractors Ranked Across Toronto and the GTA

Last updated: By Below-Grade Records Desk

225 basement waterproofing contractors listed across the Greater Toronto Area, compiled August 2026.

19,019 Google reviews · median 4.84★ · typical $50–$80 per linear ft (Project Landscaping (Ontario)) · 82% of rated companies at 4.8★ or above · scheduling: interior work year-round; exterior excavation typically April to November

Ranking

Who ranks highest for basement waterproofing in the GTA?

  14. ROOTERWORX14

    ROOTERWORX

    6.0 km from Mississauga centre

    MississaugaBasement Waterproofing

    Its own website describes below-grade water work

    (416) 400-2685Call

225 companies are filed under basement waterproofing in the Greater Toronto Area, holding a median 4.84★ across 19,019 Google reviews. 193 of them describe this work on their own website; for the other 32 we go on the category Google files them under and say no more than that. Budget $50–$80 per linear ft for interior drainage, basic system, the GTA figure Project Landscaping (Ontario) publishes. Order comes from review data and how complete each record is. Nobody buys a place on it.

Prices

What does basement waterproofing cost in the GTA?

Project Landscaping (Ontario) puts interior drainage, basic system at $50–$80 per linear ft. Project Landscaping (Ontario) prices interior full perimeter system with drainage membrane at $70–$120 per linear ft. Ontario charges 13% HST on top, and GTA contractors quote before tax. 8 line items are broken out below, each credited to the source that published it.

GTA basement waterproofing prices as published, August 2026. Every row names its source.Some of these prices are published by contractors this directory also lists. Those rows are marked. A company cannot buy a ranking position by supplying a figure.

ItemTypical rangeUnitSource
Interior drainage, basic system (trench, weeping tile, tie to sump). Source lists $5,000-$8,000 as the typical whole-project total$50–$80per linear ftProject Landscaping (Ontario)
Interior full perimeter system with drainage membrane. Source lists $7,000-$12,000 as the typical whole-project total$70–$120per linear ftProject Landscaping (Ontario)
Interior premium system with backup pump. Source lists $10,000-$18,000 as the typical whole-project total$100–$180(typ. $140)per linear ftProject Landscaping (Ontario)
Interior waterproofing, whole basement perimeter, typical GTA home (all in)$3,500–$15,000+per projectDryShield (Toronto & Southern Ontario)also listed in this directory
Exterior membrane waterproofing, GTA market rate$150–$300per linear ftNusite Group (Toronto)also listed in this directory
Exterior excavation and membrane, standard 7-foot basement, single wall (dig to footing, parge, rubberized membrane, dimpled board, new weeping tile, backfill)$250–$400per linear ftOCM Excavation & Construction (Richmond Hill, serving Toronto & GTA)
Exterior excavation and membrane, 8-foot basement (most 1960s and newer Toronto bungalows)$300–$475per linear ftOCM Excavation & Construction (Richmond Hill, serving Toronto & GTA)
Exterior waterproofing, single 30-foot wall on a Toronto semi, all in (excavation, hauling, parging, membrane, drainage board, weeping tile, backfill)$8,500–$13,500per wallOCM Excavation & Construction (Richmond Hill, serving Toronto & GTA)

Open the full basement waterproofing cost guide

Coverage

Which part of the GTA is the job in?

Pick the city or neighbourhood to narrow the list to companies working there. 13 areas have enough listed basement waterproofing contractors for their own ranked page, each built from that area's review data alone.

Ranking

How is this ranking built?

Position starts with a Bayesian-adjusted Google rating, which weighs how many people reviewed a company as well as what they scored it, so a 5.0 resting on three reviews does not sit above a 4.8 resting on three hundred. A small amount is added for records that publish a website, a phone number and at least three photos. 82% of the rated basement waterproofing contractors here reach 4.8★, so the gaps between neighbouring positions are narrow and worth reading. Positions move as new reviews land, and no company is told about it in advance. Read our full methodology.

Frequently asked questions

What does basement waterproofing cost in Toronto and the GTA?

Project Landscaping (Ontario) publishes $50–$80 per linear ft for interior drainage, basic system, and Project Landscaping (Ontario) publishes $70–$120 per linear ft for interior full perimeter system with drainage membrane. Those are pre-tax figures, so add 13% HST. The basement waterproofing cost guide on WaterproofingIndex sets out every line item beside the source that published it.

How do I pick a basement waterproofing contractor in the GTA?

Three written quotes, each naming the same wall and the same scope, is the only comparison that means anything below grade: one firm can price an interior drain while another prices an excavation, and the totals will not be comparable. The shortlist above is every basement waterproofing contractor on record here, 225 of them, sitting at a median 4.84★ on a median of 35 Google reviews apiece. Ask each one for proof of insurance and for two addresses within a few streets where it did the same job.

When can basement waterproofing be scheduled in Toronto?

Interior work year-round; exterior excavation typically April to November. Frozen ground is what fixes the calendar: anything needing an open trench waits for the thaw, while work done from inside the basement carries on all winter. Ask each quote which parts of its scope need the ground open, because that single answer decides your start date.

Do these jobs need a permit, and does the quote include HST?

Ontario charges 13% HST on plumbing and waterproofing work, and GTA contractors publish their ranges before tax, so add it before comparing. Permits follow the scope, not the price. The City of Toronto requires a building permit and an inspection for a backwater valve, and charges an underpinning permit fee for lowering a basement or cutting a new below-grade entrance. Where a permit applies, the basement waterproofing cost guide prices it as its own line with the City's own figure.

Will the City help pay for basement waterproofing in the GTA?

Not for the waterproofing itself. Toronto's Basement Flooding Protection Subsidy Program is aimed at protective plumbing devices, meaning a backwater valve, a sump pump and severing the old foundation drain connection, rather than at excavating a wall and membraning it. The program is Toronto's own, so outside the city read your own municipality's page rather than assuming the same terms. Eligibility, the devices covered and the current amounts are all set by the City and do change, so read the program page on toronto.ca before you commit, and ask the contractor how many of those applications they have filed.

Can a company pay WaterproofingIndex for a higher position?

No, and there is nothing to buy. The order comes from a Bayesian-adjusted Google rating plus a small amount for records that publish a website, a phone number and photos. With 82% of rated basement waterproofing contractors at 4.8★ or better, positions here separate on narrow margins. The methodology page sets out the formula.

Questions to ask your contractor

  • Are you quoting interior drainage, exterior excavation, or both, and what rules out the other one? Interior versus exterior, side by side
  • If you are digging outside, how far down do you go, and does it reach the footing? Sourced per linear foot pricing
  • Which membrane and which dimple board go on the wall, by product name?
  • Is the weeping tile being replaced, or flushed and left in place?
  • What exactly does the warranty cover, how long does it run, and does it transfer to the next owner?

Coverage

Where to go next

Below-grade problems rarely stay in one category. These are the other Greater Toronto Area rankings and guides on WaterproofingIndex.