Reviewed by the GTA Pool Contractors editorial teamLast reviewed How we research
Who is included
A company must publish a phone number, a working website and a logo from that site. 10 in Markham cleared it; one-company cities are not published.
How the order is set
Google review count, highest first. Star rating and then name break ties. No payment, no sponsored slot, no editorial favourite.
What is not claimed
No workmanship inspection, no insurance or WSIB check, no endorsement. The rating is Google's and is linked to the live listing.
10 companies · Markham
The top three by review volume, then the rest of the list. Every name links to a profile with the full record and a link to the company's own Google listing.
Rank 1
Markham · Pool builders
Builds new inground pools; renovates and resurfaces existing pools; replaces vinyl liners; repairs pumps, heaters and equipment.
Rank 2
Markham · Pool builders
Builds new inground pools; renovates and resurfaces existing pools; replaces vinyl liners; repairs pumps, heaters and equipment.
Rank 3
Markham · Hot tubs & spas
Maintains pools and balances water; services hot tubs and spas; installs safety and winter covers; installs heaters and equipment.
Review counts were read in 5 November 2026 and change over time. The linked Google listing is the live figure. Inclusion is not an endorsement. Not sure who to shortlist? Take the guided match.
Local context
Markham's clay-heavy soil holds frost longer, so openings often slip a week past Toronto. Budget for a late-May opening rather than the May long weekend.
The order on this page is review volume, not price or quality. For the numbers behind a build, the GTA inground pool cost guide uses published ranges, checked and dated.
Compare two names directly in the side-by-side contractor tool — it shows which one lists the job you actually need.
Get three quotes, then compare the line items.
The most repeated advice in the corpus, 40 comments deep. Three totals tell you nothing when one quote leaves out the heater; three itemised quotes tell you what the job actually costs.
Read the exclusions, not the headline.
39 comments were about scope and change orders. The gap between the quote and the invoice is usually something the contract never named — decking, fencing, the gas hookup, or what happens if the dig hits rock.
Find out who digs, and who finishes.
The crew that excavates is often not the crew that closes the job, and owners describe the handoff as where communication and quality slip. Ask for the names, and the dates, in the contract.
Ask for the certificate, not the logo.
Ontario has no general pool-builder licence. Ask for liability insurance, a WSIB clearance certificate and, for gas work, TSSA registration. Twenty comments on this, same answer every time: get the document.
Keep the last payment until you are satisfied.
The deposits thread is small but consistent — money out before the work, and the leverage goes with it. Pay in stages, hold back a meaningful final payment, and never e-transfer a deposit to a personal name.
Markham FAQ
The full standard is in the methodology. If a record is wrong, the correction process is public.
Every company on this page has a phone number from its Google listing, a working website and a logo taken from that site. 10 Markham companies met that check. It is a reachability test, not an inspection, and it is not a complete census of every pool business in Markham.
No. No company paid to appear or to move up. The order is Google review count, highest first, with star rating and then name as tie-breaks. A high review count means a company has done a lot of jobs and asked for reviews — it does not prove the work was good.
The stars are Google's, taken from each company's Maps listing and linked so you can check the live figure. They are not reviews collected on this site, and the counts change over time. Read the recent one- and two-star reviews before you book; they usually describe the failure mode better than the five-star ones.
Open the free comparison tool linked on this page, pick two companies and choose the job you are hiring for. It shows what each one lists, their phone and website, and which one covers that job — then gives you the five questions to ask both before you sign anything.
Tell us the job and your postal prefix. We reply with available local companies — free, no obligation, no sales visit.