Water systems · Vinyl pool liner
How long does a pool liner last?
The baseline chart gives a vinyl pool liner about 10 years. The warranty on it says 25 — and GLI, to its credit, prints the arithmetic straight onto the card: three years of actual coverage, then the owner pays half the price of the replacement, then three quarters of it. The last fifteen years of that 25-year term are a discount, not a warranty.
Updated
The gap: warranty ends at 25 years; typical service life ends around 10 years. The paper runs 15 years past the typical service life — coverage that long is almost always prorated, thinning well before it ends. Warranty document (GLI Pool Products, checked 2026-08-27)
Typical service life: about 10 years
The baseline chart carries a single 10-year figure for a vinyl liner. Thickness is the first variable behind it — 20-mil and 27-mil liners are effectively different products with different careers — and water chemistry is the second. Sunlight does its work at the waterline band long before the floor shows anything at all.
Tier 3 · baseline chart (undated) Range from InterNACHI — Standard Estimated Life Expectancy Chart for Homes, checked 2026-08-27.
Freeze-thaw runs the vinyl liner's other clock: a liner that spends winter cold, with only a foot of water over the floor, shrinks — and the shrunken liner is the one that tears at the bead when it is stretched back in spring. In year-round swimming regions the liner never rests, and the sun does the same work at the waterline instead.
What the warranty paper actually says
GLI Pool Products (Inground vinyl liner standard warranty — 25-year limited, 3 years full) publishes a 25-year limited, prorated, non-transferable warranty. The warranty card prints the whole schedule in three lines: the owner pays nothing for the first three years, 50 percent of the replacement price for a liner that fails in years four through ten, and 75 percent from year eleven to year twenty-five. GLI's own literature calls it a non-transferable prorated warranty covering defects in workmanship, and asks for registration within ten days of purchase. The company's Premier Value liners carry a 20-year term on the same pattern — one year full, then 50 percent to year five and 75 percent to year twenty. Read either one as a short full-coverage period with a long tail of shrinking credit attached.
The warranty document itself , checked 2026-08-27.
What shortens it
- Water chemistry left out of balance — low pH and high free chlorine both attack the printed pattern and then the vinyl under it
- Undissolved chemicals settling on the floor, which bleach the print exactly where they land
- Chlorine vapor held under a cover through the season, which ages the vinyl above the waterline from the air side
- Sunlight on the waterline band, which goes stiff and papery years ahead of the rest of the liner
- Letting the water level fall, or draining the pool, which lets a liner shrink and then forces it to stretch back
- Groundwater rising behind the wall panels, which floats the liner and works the bead out of its track
- Scuffing from cleaning equipment, ladders and pool furniture dragged across the vinyl
Signs of wear to look for
- The pattern fading or washing out along the waterline while the floor still looks new
- Vinyl gone stiff at the top, so a fold cracks instead of springing back
- Wrinkles across the floor or the shallow-end slope that were not there last season
- The bead pulling out of its track along a wall or at a corner
- A seam opening at a step, a corner or a return fitting
- Water loss that keeps going with the pump switched off and the ground around the equipment dry
Water loss that continues with the pump off can be the shell, the plumbing under the deck or the ground behind the wall rather than the liner itself — that is an inspection question, not a web-page question.
Related water systems
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- Sump pump about 7 yrs
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- Water supply lines 40–75 yrs
- Sewer line 50–80 yrs