The size printed on an old pool invoice is a useful clue, but it is not enough to order a replacement liner. The new liner must fit the pool that exists today, including its wall height, floor shape, corners and attachment style. Here is what a homeowner can measure and photograph before asking for a quote, and where a professional measurement becomes important.
Use these measurements to start a conversation, not to place a custom liner order. Lakeshore Pool & Deck confirms the dimensions and site condition before a liner replacement scope is finalized.
First, identify the pool and liner type
Write down whether your pool is above-ground or in-ground and whether it is round, oval, rectangular or another shape. If you know the pool manufacturer, model or approximate age, include that information. Take a wide photo from each side and a close photo of where the liner attaches at the top of the wall.
The attachment style matters. An above-ground pool may use an overlap, beaded or other liner system. A replacement with the wrong attachment style can be unusable even when the diameter is correct. GLI Pool Products’ liner forms show how many details beyond length and width can matter for an in-ground liner.
Measuring a round above-ground pool
Measure the inside diameter from wall to wall through the centre of the pool. Take that measurement in two directions and record both results. Measure the wall height from the bottom of the wall to the point where the liner attaches. Photograph the top rail or bead receiver and the transition where the wall meets the floor.
Do not rely only on a label such as “24-foot round.” Pools can be slightly out of round, and wall heights and liner attachment styles differ. LinerWorld’s measuring guide likewise recommends measuring the actual pool rather than relying on previous notes.
Measuring an oval above-ground pool
Measure the inside length through the centre from end wall to end wall and the inside width at its widest point. Record the wall height and photograph the straight sides, curved ends, structural supports and liner attachment. If the floor has a deeper area rather than a standard flat bottom, mention that before a liner is selected.
If the walls look bowed, shifted or damaged, include photos. A new liner will not correct a structural problem, and that condition may change the replacement scope.
What to record for an in-ground vinyl pool
Start with a simple overhead sketch. Mark the shallow end, deep end, steps, benches, corners, lights, skimmers and other unusual features. Record the approximate overall length and width and any depth information you already know. Take clear photos of each wall and the full pool from above where it is safe to do so.
Those details help with an initial assessment. The final measurements for a custom in-ground liner are more involved. Floor slopes, break lines, hopper dimensions, wall heights, corners and step shapes all affect the pattern. A liner manufacturer may require a pool-specific measuring form, and the installer should verify the measurements before ordering. Do not drain an in-ground pool solely to take measurements without professional direction.
What to send when requesting a liner assessment
An initial request is most useful when it includes:
- The property location and pool type.
- Approximate length, width and wall height or depths.
- The liner attachment style, if known.
- Photos of the full pool, liner edge, steps, fittings and equipment access.
- Any leaks, wrinkles, stains, tears or visible wall movement.
- Your preferred timing for the replacement.
If you are unsure of a number, label it as approximate. An honest estimate is more useful than a precise-looking guess. Our vinyl liner replacement page explains the assessment and fitting process for both pool types.
For a Barrie or Simcoe County pool, request a liner assessment with the details and photos you have. We can review the pool before confirming the replacement scope and final measurements.