Replacing an above-ground pool liner is one of the bigger pool projects a homeowner will tackle, and it’s easy to feel buried by options — round vs. oval, 48 vs. 52 inch walls, overlap vs. beaded vs. unibead, 20 mil vs. 25 mil vinyl. The good news is that there are really just four decisions you need to make. Get them right and the liner will fit, last 8–15 years, and look great. Get them wrong and you’ll be wrestling wrinkles for an entire afternoon — or worse, ordering a second liner.
The four decisions that matter
1. Match the pool’s exact dimensions (round, oval, and wall height)
Above-ground liners are sold by pool size and wall height. The two most common wall heights are 48 inches and 52 inches. Measure your existing pool wall before ordering — do not assume it’s 52 because that’s “normal” today. For oval pools, you also need to confirm the brand and style of buttress (the metal frame on the sides), because some oval liners are cut specifically for certain frame styles.
2. Pick the right hanging style
This is the single most common ordering mistake. Above-ground liners hang from the top of the pool wall in one of three ways:
- Overlap — the liner drapes over the top of the wall and is held in place by coping strips. Cheapest, oldest style. Best if your existing pool was originally built with overlap.
- Beaded — a thickened bead snaps into a separate bead receiver track that runs around the top of the wall. Cleaner look, but requires the bead track to already be installed.
- Unibead (J-hook) — a hybrid that can be used as a beaded liner if you have a bead receiver, OR cut into an overlap-style strip if you don’t. This is the most flexible option and what most homeowners should buy if they’re unsure.
3. Pick a vinyl thickness
Vinyl is measured in mils (1 mil = 1/1000 inch) or gauge. Common thicknesses for above-ground liners are 15 mil (entry-level), 20 mil (standard), and 25–30 mil (premium). Thicker vinyl resists punctures, holds color longer, and adds 3–5 years to typical liner life. If your pool is in a yard with heavy tree drop or pets, premium thickness is worth the modest upgrade cost.
4. Choose a pattern that will hide future scuffs
Solid white or solid blue liners look great on day one and unforgiving on day 500. Patterned liners (boulder, pebble, tile band) hide the inevitable scratches and stains better and tend to maintain perceived quality for the full life of the liner. This is purely aesthetic, but it’s the difference your eye notices in year three.
Sizing examples from our stock
Here’s how the dimensions translate to actual products. All three of these are GLI Unibead Boulder pattern in different sizes — useful as a baseline if you’re trying to figure out roughly what a liner runs for your pool size:
GLI 18′ Round 52″ Unibead Boulder
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GLI 24′ Round 52″ Unibead Boulder
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GLI 15′ x 30′ Oval 48″ Unibead
Shop NowWhat else do you need at install time?
Most liner failures happen at install, not from use. Order these alongside the liner so you only do the job once:
- Liner pad or floor cushion — a foam underlayer that goes between the pool bottom and the liner. Smooths out small pebbles and roots and dramatically extends liner life.
- Wall foam — 1/8 inch foam adhered to the inside of the pool wall before the liner goes in. Makes the inside of the pool feel softer and protects against scuffs.
- Cove kit — foam triangles that go at the base of the wall to prevent the liner from being pushed into the corner by water weight.
- New gaskets and faceplates for the skimmer and return fittings — reusing old gaskets is the #1 source of post-install leaks.
When in doubt, send us a photo
If you’re uncertain about your pool’s hanging style or wall height, send PST Pool Supplies a few photos — one of the inside top edge of the wall (so we can see how the current liner attaches) and one of the pool from outside. We’ll match the right liner the first time, so you’re not living with the wrong hardware for the next ten years.