What Is An Expandable Pool Liner? How Does It Work?


When you get an above-ground fibreglass pool, you can choose what kind of liner you want for the pool. An option that’s growing more popular among above-ground fibreglass pool owners, is expandable liners. Other kinds of liners you can get include uni-bead, beaded, and several other kinds of liners. Of these, expandable pool liners are less common. There’s a special reason for this as well.

You only need an expandable pool liner when your fibreglass pool has a centre that’s deep. You’ll also need this kind of liner when your pool has a deep end – deeper than at least one foot.

When Should You Get An Expandable Pool Liner

Some people end up ordering expandable pool liners because they feel that these are better than standard liners. However, this isn’t necessarily the case. In reality, if a standard liner is suited to your fibreglass pool, then it will perform better than an expandable liner.

Say you’re planning on getting a fibreglass pool with a deep centre or a deep end. In this case, an expandable pool liner is what you should opt for. If you only want the centre or the end of your pool to be one foot deep, you won’t need an expandable pool liner. This is because standard pool liners are equipped with the capacity to accommodate pools that are one foot deep, or less.

What’s The Difference Between An Expandable Liner And An Overlap Liner?

Expandable liners aren’t really made of material that stretches better. It’s made of the same material that overlap liners are made of. The main difference here is that the side-wall material of an expandable liner is around 72″, instead of 60″, which is seen in overlap liners.

With an extra foot’s worth of material to support it, you can better accommodate a pool with a deep bottom. Overlap liners, on the other hand, can be adjusted on the top part of the wall of the pool. As a result, only a portion of the liner actually ends up being used for the fibreglass pool. The rest of the liner will hang over the pool’s wall, creating a draping effect that leads outside.

Expandable liners, on the other hand, come with more material that can be used to accommodate the deeper parts of the pool.

The Options That Are Available When It Comes To Expandable Liners

There are just two major manufacturers that produce expandable liners. This means that you won’t get much of an option when investing in these. You’ll probably find yourself with an expandable liner that’s coloured solid blue, or one that is solid blue but with a bottom that’s printed. The third option is an expandable liner that’s completely printed.

Of these, the fully printed expandable liners are more popular. This is because the printed liners tend to last longer than the ones that are just solid blue.

Using An Expandable Liner In A Pool With A Flat Bottom

You can use an expandable pool liner for above-ground pools that have flat bottoms. It will, however, be more difficult to install, as you’ll be left with an excessive amount of material, hanging over the walls of the pool. This won’t be more than around two feet of material, but it can still affect how your pool looks from the outside.

Although the inside part of the pool will look good, the outside can look cluttered. Once you’ve filled your fibreglass pool with water, you can manually cut off the excess part of the liner. This can be time-consuming, but it can be done.

How Can You Install An Expandable Pool Liner?

To install your expandable pool liners you’ll need up to twenty-four clamps that are rubber tipped. You’ll also need a push broom that’s soft, screwdrivers, a trowel with a rounded end, and a trusty razor knife.

Here’s how you install your expandable pool liner:

1. Removing The Existing Liner

First, drain the water in your above-ground pool. Then, when your pump starts to suck in air, use your razor knife to cut the liner from the base of the pool wall. Then, pull the liner up so the remaining water can be drained out of the pool.

Then, cut out coping strips as well as the top rail. You can replace the top rail, but avoid doing that to the coping strips.

2. Prepping The Floor And The Walls

Now, carefully clean dirt as well as deposits from your pool. Decide also, whether you want to replace the pool cover or not. Then, you’ll need to use your brooms as well as the trowel, to smoothen out the sand on the floor of your pool. Get rid of any debris, or rocks, and ensure that high and low spots are filled.

3. Installing The Liner

When installing an expandable liner, you’ll need to pay attention to the next step. Take your liner out in a clear area, and use duct tape, to mark the seam intersections. Then, fold the liner like you would fold an accordion. Carry the pool liner, with one person holding each end of the liner, till you’re at the shallow end of the pool. Here, pull the liner till it’s over your pool. Remember to pull it over the top rails as well.

Now, look at the marks you made with your duct tape. This can help you adjust the slack of your pool liner. When it’s in position, you can clamp the liner to the part around the top rail. Do this around the entire pool.

4. Refilling The Pool

Next, you’ll need to refill the water in your pool. During this step, allow the pool liner to stretch. Remember that for around every one-tenth of water that goes into pool, you need to release around one-tenth of the liner. Do this slowly, and let the liner slip in a few inches into the pool. Then you’ll need to reclamp your liner to the part around the top rail.

It’s better to fill your pool using a truck. Although more expensive, you can fill your pool in under two hours. If you use a hose to fill your pool, then this can take up to two days.

Once you’ve stretched the expandable pool liner into place, you’ll find there are still a few inches of the liner hanging outside the walls. You can trim off excess material that’s hanging over the pool walls. Finally, screw the skimmer on and place the faceplates back where it needs to be.


An expandable pool liner is suitable for above-ground pools where either the centre or the pool, or the deep end, is deeper than one foot. You can ask your pool builder perth to install your expandable pool liner for you if you’re unsure about how to do it yourself. Use this guide to learn more about expandable pool liners, as well as how they’re installed.