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WaterproofingIndex

Every waterproofing contractor in your part of the GTA, side by side

Water in the basement is an expensive problem to shop for badly. WaterproofingIndex lists the Greater Toronto Area companies that fix it, orders them by a formula we publish in full, and stops there. A company that has claimed its listing publishes the number to call; for every other one, you send a request instead. Nothing is sold on this site.

See the ranked listBrowse cost guides

Last updated: By Below-Grade Records Desk

384
Greater Toronto Area businesses
6
Service categories
4.9★
Average Google rating

Companies

Which below-grade trades are listed here?

Wet basements are not one trade. Sealing a foundation wall from the outside, injecting a cracked poured wall, replacing failed weeping tile, dropping a floor by underpinning and fitting a backwater valve are separate skills, often separate companies, and quoted on separate units. WaterproofingIndex splits them into 6 categories so the shortlist you read is the shortlist for your actual problem. Behind the categories sits a dataset of 384 Greater Toronto Area businesses scored by the published 0-100 score, averaging 4.9★ across 345 rated companies. Each category hub also links to a cost guide whose every figure names the Ontario contractor it came from. Pick the work you need below.

Ranking

The highest-ranked companies right now

Ranked by the WaterproofingIndex Score

8 companies lead the Greater Toronto Area list on the August 2026 data. The order comes from the score described further down this page, so a long record of solid reviews beats a short perfect one. Each card carries the real Google rating, the real review count and a way to reach the business.

Coverage

Where in the GTA does the coverage reach?

Basement water is a neighbourhood problem. Age of housing stock, clay soil, the depth of the storm sewer and whether a street was built with weeping tile connected to the sanitary line all change what a contractor will recommend, so each of the 384 listings is pinned to a specific Toronto neighbourhood, borough or GTA city rather than a vague service radius. That gives 35 mapped areas across downtown Toronto, North York, Scarborough, Etobicoke and cities such as Mississauga, Vaughan and Markham. Measured by listed companies, the deepest coverage today is Toronto (134), Mississauga (34), Vaughan (16), Oakville (16), Burlington (16). Open the area nearest your house to see who works there, ranked the same way as everywhere else.

Browse all GTA areas

Prices

What does this work cost in Toronto?

Below-grade work is quoted by the linear foot of wall, by the square foot of floor or as a whole job, which is why two quotes for the same basement can look unrelated. Interior waterproofing, whole basement perimeter, typical GTA home is published at $3,500 to $15,000+ per project by DryShield (Toronto & Southern Ontario). Exterior weeping tile replacement is published at $200 to $450 per linear ft by AquaMaster Plumbing (Toronto). Ontario charges 13% HST on top of figures like these.

Every number in every guide is copied from a named Ontario contractor or authority and shown with that name beside it, so you can open the source and check it. Where two sources disagreed, the range was widened instead of one being picked. Read the guide for your job before the first company walks down your stairs, and you will know which line items belong in the quote.

Open the cost guides

Companies

Using the directory

There is no account and no wait. Read the ranked list, read the going rate, then reach the company you want: call it directly if its listing is claimed, or send a request from its profile if it is not.

  1. 1. Narrow it down

    Start from one of 6 categories or your own area, and read companies in rank order rather than ad order.

  2. 2. Learn the going rate

    Open the matching cost guide and note the unit the work is priced in, so you can tell a fair quote from a guess.

  3. 3. Reach the company

    A company that has claimed its listing publishes the number it wants you to call. For every other row, a request form on its profile reaches WaterproofingIndex.

Ranking

The ranking formula, in short

A raw star rating lies when the review count is small, so the score starts by blending each company's Google rating with the dataset average of 4.9★ using a 10-review prior. A rating only reaches its raw star value once enough reviews back it. That is worth 40 of the 100 points. Another 35 comes from what a company states on its own website: insurance, WSIB coverage, years going and trade bodies, each one stored with the sentence it was read from, and none of it checked by us, because Ontario licenses nobody for this work. The last 25 is how complete and reachable the record is, including the themes that keep recurring across a company's own reviews, and the complaints. Put together, a 5.0 company with 4 reviews and no website lands below a 4.8 company with 300 reviews, a live site and photos. The same arithmetic runs over all 384 listings, and there is no input for money.

Read the full methodology

Questions

Ask these before you sign anything

A waterproofing quote is easy to compare on price and hard to compare on scope. These questions drag the scope into the open, which is usually where two quotes for the same basement actually differ.

Common questions

What decides which contractor sits at the top of a WaterproofingIndex page?

One published formula, applied to every listing: a score out of 100 over three pillars. Reviews come first, adjusted so a 5.0 built on 4 reviews cannot outrank a 4.8 built on 300. Then what a company states on its own website, each statement stored with the sentence it was read from. Then how complete and reachable its record is. Nothing else moves a position, and no payment of any kind does.

Can I book a waterproofing job through WaterproofingIndex?

Not directly. This is a directory, not a booking service. A company that has claimed its listing publishes its own phone number and website, and you deal with it directly from the first minute. Every other listing carries a request form instead; what you send through it reaches WaterproofingIndex, and your details are not published on the site and are not sold.

Does WaterproofingIndex charge homeowners or contractors?

Neither. Reading all 384 listings and every cost guide is free, and a business pays nothing to appear or to correct its details. Because nobody pays, nobody can buy a position.

Which parts of the Greater Toronto Area are covered?

Coverage runs from downtown Toronto and the boroughs of North York, Scarborough and Etobicoke out through 35 mapped areas, including Mississauga, Vaughan, Markham and Oakville. Across those areas sit 384 businesses in 6 below-grade service categories.

How old is the data?

Every star rating and review count is public Google Maps data, pulled for the August 2026 dataset. 345 of the 384 listed businesses carry at least three Google reviews, and across those the average sits at 4.9 stars. The rest are listed without a score. Rankings are recalculated when the data is refreshed, so a company that stops earning good reviews slides down.