How WaterproofingIndex ranks companies
Last updated: By Below-Grade Records Desk
Any ranked list is worthless unless you can see what produced the order. Here is the whole of it: a Bayesian-adjusted Google rating, plus four small boosts for how complete a record is. No business can pay for position, and there is no input in the formula that money could touch even if one tried. Read this page and you can recalculate any rank on the site yourself.
The formula
Each company carries one score, built from two parts: an adjusted version of its Google star rating, and small additions for signals that its record is complete. The calculation is deterministic, so identical data always produces an identical order, and anyone can audit a position among the 384 listings.
score = bayesian_rating + completeness_boosts
bayesian_rating = (v / (v + 10)) × R + (10 / (v + 10)) × mean
where R = Google rating, v = review count, mean = 4.85
Why the star rating is adjusted first
A perfect rating on a handful of reviews carries almost no information. The fix is to treat every company as though it opened with 10 imaginary reviews sitting at the dataset mean of 4.85 stars, then let its real reviews pull the score away from that. A company with hundreds of reviews barely feels the prior. A company with four feels it heavily, until it earns more history.
This shrinkage approach is the same idea behind IMDb's Top 250 and similar rankings. In practice it means a long record at 4.8 stars finishes above an untested 5.0, which is the order most homeowners would choose anyway when hiring for work that has to hold back water for decades.
What the four boosts reward
After the adjusted rating, up to 0.35 is added for signals that a business is real, reachable and still trading. These are observations about the record, not judgements about workmanship, and they are small on purpose: they separate companies that are otherwise close, and never override reputation. A flawless rating with no boosts still finishes above a weaker one with every boost.
| Signal | Boost |
|---|---|
| Active website | +0.15 |
| Listed phone number | +0.05 |
| 3 or more photos | +0.10 |
| Posted business hours | +0.05 |
A worked example
Two made-up companies, scored against the live August 2026 dataset mean of 4.85 stars. A holds a perfect rating on 8 reviews and shows a website and a phone number. B holds 4.8 stars over 280 reviews with every signal present. Follow the two middle columns to see where the order is decided.
| Company | Rating | Reviews | Bayesian | Boost | Final |
|---|---|---|---|---|---|
| Example Waterproofer A | 5.0★ | 8 | 4.919 | +0.20 | 5.119 |
| Example Waterproofer B | 4.8★ | 280 | 4.802 | +0.35 | 5.152 |
B finishes first, 5.152 against 5.119. The perfect 5.0 shrinks toward the mean on only 8 reviews, and B's volume plus its full set of signals holds the top spot.
What gets dropped or pushed to the bottom
Businesses marked permanently closed on Google are removed outright, since pointing a homeowner with a flooding basement at a closed shop helps nobody. Companies with fewer than 3 reviews, or a rating below 4.0, keep a profile page for completeness but sit at the bottom and stay out of the top-ranked modules until there is enough of a record to judge.
Where the inputs come from
Ratings, review counts and business details are read from public Google Maps profiles, then each record is checked against the company's own website for the services it actually offers, its photos and its contact details. Pricing across 6 categories is researched separately, and each figure is published with the name of the Ontario contractor or authority it came from so you can trace it. Nothing private is scraped and no reviews are bought.
How often the numbers move
The current dataset is stamped August 2026. Review data is re-pulled and the ranking re-run on a rolling basis, so a position tracks reputation rather than freezing on the day a company was first indexed, and each page shows its own last-updated date. If a business has been sold, has closed or has details that are wrong, tell us through the contact page and the record is updated between refreshes.
What a high rank does not tell you
It tells you a company has a strong public review record and a complete one. It tells you nothing about the crew that will show up at your house. This site does not check WSIB coverage, liability insurance, licences or workmanship guarantees, and it has never inspected a job. For work that involves excavating beside a foundation or cutting a slab, ask for proof of insurance in writing, get the scope itemised by more than one company, and read the recent reviews rather than the average. The shortlist is ours. The decision stays yours.
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