20 mil, 27 mil or 30 mil — what the extra vinyl actually buys.
Interactive matrix
Compare the three gauges side by side
Select a pool size, then tap a row for the warranty schedule and the jobs that gauge suits. Prices are installed, before HST, and assume a standard rectangle with normal access.
Pool size
Installed, before HST · standard rectangle
| Gauge | Installed (16 × 32 ft) | Expected life | Puncture | UV | Warranty |
|---|---|---|---|---|---|
| 20 milStandard | $4,900 – $7,600 | 8–12 seasons | 10 yr pro-rated | ||
| 27 milHeavy duty | $5,300 – $8,200 | 12–16 seasons | 12 yr pro-rated | ||
| 30 mil / hybridPremium | $5,700 – $8,800 | 15–20 seasons | 15 yr pro-rated |
Best for — 27 mil
- Family pools with dogs and diving boards
- Full-sun lots with no shade
- Pools kept open late into September
The usual sweet spot in the GTA: roughly $300–$700 more than 20 mil on a 16 × 32, with materially better puncture resistance.
Warranty: 100% year 1, dropping to 20% by year 12. Labour and water excluded.
Benchmark ranges, not quotes. A freeform shape, wall repair, hoist or water hauling can move a total by $1,000 or more in either direction.
What “mil” actually measures
One mil is a thousandth of an inch, so a 27 mil liner is 0.027 inches of vinyl — about the thickness of six sheets of printer paper. Measured with a micrometer in the field, most Genuine 20 mil liners read slightly under 20, and good 27 mil liners read 26–28 depending on where on the sheet you sample.
Where the vinyl is thicker, it resists punctures from poles, claws and toys and fades more slowly under UV. What it does not do is hold a failing seam together. Seam strength comes from the weld, and a bad weld fails regardless of gauge.
How to read a pro-rated warranty
A “10-year warranty” on a liner is almost never a decade of full coverage. The manufacturer covers 100% in year one and steps down each year, so a year-7 claim on a 10-year liner might recover 40% of the liner cost — and never the labour, water or disposal.
- Ask for the schedule in writing: the percentage for each year.
- Confirm whether the warranty covers seams, punctures and fading separately.
- Ask who honours it — the installer, the distributor or the manufacturer.
- Keep the liner's serial number and the installation invoice.
In practice the installer's workmanship warranty matters more in the first two seasons than the manufacturer's decade-long schedule. Get both, in writing, before the deposit.
What to spend the difference on
If the choice is 27 mil versus a 20 mil liner plus wall repair, take the repair. A corroded panel or soft floor will ruin a premium liner faster than a cheap one will fail on a sound shell. The same logic applies to a new skimmer faceplate, fresh gaskets and a properly fitted safety cover.
Typical GTA install
$4,500 – $11,600
Across 20/27/30 mil and 12 × 24 to freeform, before HST.
City-by-city liner pricing
Gauge questions
What homeowners ask before upgrading
Is 27 mil worth it over 20 mil?
For most GTA family pools, yes. On a 16 × 32 rectangle the upgrade usually adds $300–$700 installed, buys roughly three to five more seasons, and resists punctures and UV fade noticeably better. It is not worth it when the wall panels or floor are failing — fix the shell first, because vinyl thickness cannot compensate for a bad substrate.
Does a thicker liner mean a longer warranty?
Partly. Manufacturers typically publish 10, 12 and 15-year pro-rated warranties for 20, 27 and 30 mil liners. Pro-rated means the coverage percentage falls each year and labour is excluded, so a year-8 claim on a 10-year liner covers very little. Read the schedule, not just the headline number.
How do I know the quote is actually for 27 mil?
Ask for the liner manufacturer, pattern name, gauge in mil, and the warranty certificate in writing before paying a deposit. A quote that says “heavy duty” or “premium” without a number is usually 20 mil. Reputable fitters put the gauge on the contract because it is the line item buyers compare.
What does the 30 mil / hybrid option add?
A thicker base vinyl, often with a reinforced or hybrid construction. Expect roughly $800–$1,200 more than 20 mil on a 16 × 32. It makes sense on high-traffic pools, exposed lots and commercial use. On a shaded, lightly used pool the extra money is better spent on wall repair, new gaskets or a proper safety cover.
Do liner prices change by GTA municipality?
They do, mostly because of access and travel rather than vinyl cost. Toronto and Oakville jobs with narrow side yards or hoist requirements can run 10–20% above Durham or Peel jobs of the same size. Compare installed totals for the same gauge and pool dimensions, not headline “starting from” prices.
Get the gauge, the warranty and the price in writing.
Send the job once and compare up to three local fitters on the same pool size and vinyl thickness.