Transparency
Our Methodology
How we source contractor data, rank listings, and handle sponsored placements — so you can trust what you see.
On this page
Where our data comes from
All contractors listed on RadonFinder.ca hold active C-NRPP (Canadian National Radon Proficiency Program) certification. Our initial dataset was sourced from the public C-NRPP registry and imported in early 2025. We refresh data periodically and contractors can claim and update their own listings at any time. We do not list uncertified contractors. C-NRPP certification is the standard recognized by Health Canada for radon testing and mitigation professionals.
How listings are ranked
Listings are sorted in two steps: 1. Listing tier — Premium listings appear first, followed by Verified, then Basic. This is a fixed sort priority, not a score. 2. Profile score (0–100) — within each tier group, contractors are sorted by their score. The score is calculated automatically and updates whenever profile data changes.
| Factor | Weight |
|---|---|
| Phone number | 15 pts |
| Website | 15 pts |
| Business description | 15 pts |
| Service address | 10 pts |
| Service areas | 10 pts |
| Verified listing | 10 pts |
| Google rating | 10 pts |
| Customer reviews | 10 pts |
| Photos | 5 pts |
Listing tiers
All contractors appear under one of three tiers. Tier determines sort priority in search results — it does not affect the profile score directly. Basic — the default for all listed contractors. Profiles are populated from public C-NRPP data and appear after Verified and Premium listings in results. Verified — free. Awarded when a contractor claims their listing and our team confirms the C-NRPP number matches the business. Verified listings rank above Basic listings and unlock the ability to add photos and manage reviews. Claiming a listing also contributes 10 points to the profile score. Premium — paid. Contractors on a Premium plan are placed at the very top of results within their market, above all Verified and Basic listings. Premium is the only paid listing option — Verified costs nothing.
Sponsored placements
Some listings appear at the top of province or city pages with a "Sponsored" label. These are paid placements purchased through our Advertise program. Sponsored listings are always clearly labelled and appear above organic results. Sponsoring a placement does not change a contractor's profile score or their organic ranking. Organic results are sorted by tier and score as described above. Sponsored slots are limited per market (province and city) to ensure they remain meaningful. Availability is shown in real time on the Advertise page.
Claiming a listing
Contractors can claim their listing by verifying their email address. Once a claim is submitted, our team reviews it to confirm the C-NRPP number matches the claimed business. Once verified, the listing is upgraded to the Verified tier at no cost. The contractor can then update their business details, add photos, respond to reviews, and access their portal.
Reviews
Reviews on RadonFinder.ca are submitted by homeowners who have used a contractor's services. We use a honeypot and basic validation to filter spam. Contractors cannot review themselves or remove reviews. We do not currently require proof of service for reviews, but we reserve the right to remove reviews that appear fraudulent or violate our terms.
Keeping data current
We encourage contractors to claim and maintain their own listings. If you notice incorrect information — wrong phone number, changed service area, lapsed certification — please contact us at hello@radonfinder.ca or use the "Is this your business?" prompt on any listing page. We aim to process correction requests within 3 business days.
Questions about our data?
We're happy to explain how any part of the system works.