A few small wrinkles in an above ground pool liner are common, and some can be worked out with the water still in the pool. Others are a sign the liner is stretched, shrinking or worn out. Here’s how to tell what’s causing yours, what you can fix yourself, and when it’s time for a new liner.

Step 1
What causes liner wrinkles

• Water chemistry. Low pH and high chlorine make vinyl absorb water, soften and stretch. A stretched liner has extra material, and the extra material wrinkles.
• Water behind the liner. Ground water from heavy rain, poor drainage or a leak can push the floor up and shift the liner.
• Age. Vinyl loses its stretch over the years. Most liners last 8 to 15 years, and older ones wrinkle more easily.
• Draining. An empty liner shrinks fast, and it rarely settles back smooth when refilled. See How Long Can You Leave a Pool Empty?
• Installation. A liner that wasn’t vacuum-seated, the wrong size, or one installed in cold weather can wrinkle from day one.
• The base. Footprints, settled sand or washed-out spots under the floor can look like wrinkles. See Above Ground Pool Base Materials.

Step 2
Read your wrinkles

Step 3
Fixing small wrinkles

Small, soft floor wrinkles can often be worked out with the water in the pool:

1. Pick a warm, sunny day. Warm vinyl is more flexible.
2. Push the wrinkle toward the wall with a soft nylon brush or a clean plunger, working from the center out. Never use anything sharp or a wire brush.
3. Go slowly. Vinyl moves a little at a time. Pulling hard can tear an old liner.
4. Fix the chemistry so it doesn’t come back. Test with a Taylor K-2005 kit and keep pH at 7.2–7.6 and free chlorine at 2–4 ppm. See our Pool Chemicals guide.

Step 4
Water behind the liner

If the floor rises or moves after heavy rain, water is getting under the pool. Sometimes it settles back as the ground dries out, but the cause needs fixing:

• Check where your gutters and downspouts drain. Point them away from the pool.
• Look at the slope. If the yard drains toward the pool, water collects under it.
• Rule out a leak. A slow leak can wash out the base from inside. See Reasons Why Your Pool Is Losing Water.

Keep the pool full while you sort it out. The weight of the water is what holds the liner down.

Step 5
When it’s time for a new liner

Wrinkles alone don’t always mean a new liner. But it’s usually time to replace it when:

• The wrinkles are hard, deep or cracking.
• They come back every season, even with good chemistry.
• The liner is also faded, brittle or leaking.
• It’s pulling out of the track or slipping off the wall.

See the full checklist in 7 Signs Your Above Ground Pool Liner Needs Replacing. Not sure? Send us a photo and Dave will tell you honestly.

Step 6
Preventing wrinkles next time

• Get it vacuum-seated. We vacuum the liner tight to the wall and floor before filling, so it sits smooth from the start.
• A smooth, solid base. We repair the base and cove before every new liner. See 5 Successful Steps to a Perfect Pool Liner Replacement.
• Install in mild weather. Spring and early summer are ideal. See Why Winter Is the Best Time to Book a Liner Replacement.
• Keep the chemistry balanced and never let pH run low.
• Don’t drain the pool unless the liner is being replaced.