What You Need to Do Before You Start

Replacing an above ground pool liner takes a full day and requires draining the pool completely. You will need to remove the old liner, clean the pool walls and floor, measure for a new liner, and install it while refilling. Most homeowners can do this alone, though a second person makes the job easier—especially when smoothing the liner as water fills it.

Before you begin, check your pool's dimensions. Measure the diameter (or length and width if rectangular), the depth, and the distance from the top of the wall to the ground on the outside. Write these numbers down. You will use them to order a replacement liner that fits your exact pool model. If you have your original pool paperwork, the liner size is usually listed there.

Decide whether to drain into your yard or into the street. Most municipalities allow yard drainage, but check your local rules first. If you have a septic system, draining a large volume of chlorinated water into the ground can harm it—contact your septic service for guidance. A typical above ground pool holds 5,000 to 20,000 gallons depending on size.

Key Takeaways

  • Drain the pool completely using a submersible pump or by lowering the water level gradually with a siphon, which takes 8 to 12 hours for most pools.
  • Remove the old liner by pulling it away from the wall and cutting it into manageable pieces to haul out, then clean the pool floor and walls thoroughly with a brush and mild detergent.
  • Measure your pool's diameter (or length and width), depth, and wall height to order a liner that matches your pool's exact specifications.
  • Install the new liner by centering it, anchoring the top edge to the wall, and smoothing wrinkles as you refill—this takes 4 to 6 hours with one person, less with two.
  • Refill slowly and check the liner for wrinkles every 30 minutes during the first few hours, adjusting it before water weight locks it in place.

Draining Your Pool Safely

Use a submersible pump to drain the pool quickly, or siphon the water out if you do not have a pump. A submersible pump rated for pools (usually 1 to 2 horsepower) will empty a 15,000-gallon pool in 4 to 6 hours. Place the pump on the pool floor, attach a discharge hose, and run the hose to your yard or street drainage. Plug the pump into a GFCI-protected outlet.

If you siphon instead, place one end of a garden hose in the pool and the other end lower than the pool water level (downhill if possible). Fill the hose with water, pinch both ends to trap the water inside, place one end in the pool and the other in your drainage area, and release. Water will flow downhill by gravity. This method is slower but requires no equipment beyond a hose.

As the water level drops, turn off the pump or siphon when the water reaches about 6 inches from the bottom. Do not drain completely dry—the last few inches are easier to remove by hand with buckets. This also prevents the pool floor from drying out too quickly, which can crack concrete or damage vinyl.

Removing the Old Liner and Cleaning the Pool

Once the water is nearly gone, pull the old liner away from the pool wall. Start at one spot and work your way around, peeling it back as you go. The liner will be heavy and wet, so move slowly. Once it is loose all the way around, cut it into large sections (roughly 4 by 4 feet) using a utility knife. Smaller pieces are easier to carry out than one giant sheet.

After the liner is out, use a stiff-bristled pool brush to scrub the pool floor and walls. Pay special attention to corners and seams where algae and debris collect. If the floor is very dirty, mix a mild detergent (a few drops of dish soap in a bucket of water) and scrub again. Rinse thoroughly with a garden hose. Any dirt or debris left behind will show through the new liner and can puncture it over time.

Inspect the pool walls and floor for sharp objects, cracks, or rough spots. Remove any rocks, sticks, or metal debris by hand. If you find a crack in concrete, fill it with pool-grade patching compound and let it cure according to the product instructions before installing the new liner. Small rough spots can be smoothed with fine-grit sandpaper, but deep damage may require professional repair.

Measuring and Ordering Your New Liner

Measure the pool diameter (or length and width for rectangular pools) at the widest point. For a round pool, measure straight across the center. For rectangular pools, measure the longest and shortest sides. Write these numbers down to the nearest inch.

Next, measure the depth from the floor to the top of the wall. Then measure the distance from the top of the wall down to the ground on the outside of the pool. This outside measurement tells you how much liner material needs to drape over the wall and anchor to the pool's edge. Add these two numbers together to get the total depth measurement you need for your liner.

Contact the pool manufacturer or a pool supply retailer with your measurements. Provide the diameter (or length and width), the total depth (inside depth plus outside wall height), and your pool model number if you have it. The retailer will recommend a liner size and thickness. Most residential liners are 20 to 28 millimeters thick. Thicker liners last longer but cost more. Order the liner and ask about delivery time—it may take 1 to 3 weeks to arrive.

Installing the New Liner

Lay the new liner flat in the sun for 15 to 20 minutes before installation. This warms the vinyl and makes it more flexible and easier to work with. While it warms, position your pump or hose at the pool so you can begin refilling as soon as the liner is in place.

Center the liner in the pool by draping it evenly over the floor and walls. Start at one point and work your way around, smoothing it as you go. The goal is to have the liner hang evenly on all sides with no major wrinkles. This is where a second person is helpful—one person can smooth while the other holds the liner in place.

Once the liner is centered, anchor the top edge to the pool wall. Most above ground pools have a track or lip at the top where the liner hooks or tucks. Follow your pool's specific anchoring method—some use clips, others use a bead that locks into a track. find the liner all the way around the pool before you begin refilling. Leave some slack so the liner can settle as water fills it.

Refilling and Smoothing Out Wrinkles

Turn on your pump or hose and begin refilling slowly. As water enters, it will push the liner down and out toward the walls. Watch for wrinkles, especially in corners and along the seams. Every 30 minutes during the first 2 to 3 hours, pause and smooth out any wrinkles you see by hand or with a pool brush. Push wrinkles toward the edges and corners where they can flatten out as the water level rises.

The first few hours are critical—once the water level reaches halfway up the pool wall, the weight of the water makes it much harder to adjust the liner. Work quickly during this phase. If you see a wrinkle you cannot smooth out, you may need to drain partially and reposition the liner, which adds several hours to the job.

Continue filling until the water reaches the proper level, usually about 6 inches below the top of the wall. This takes 4 to 8 hours depending on your pool size and water pressure. Once full, turn off the pump and let the pool sit for a few hours. Small wrinkles often disappear on their own as the water settles and the vinyl relaxes. Check the water level the next day and top it off if needed—evaporation and settling may have lowered it slightly.

Common Mistakes to Avoid

Do not drain the pool in direct sunlight if you can help it. The exposed floor can crack or warp, and the vinyl liner can degrade if left in the sun for more than a few hours. If you must drain during the day, cover the pool with a tarp.

Do not skip the cleaning step. Dirt and debris under the liner will create visible bumps and can puncture the vinyl over time. Spend the extra hour scrubbing the floor and walls thoroughly.

Do not try to stretch the liner too tight. It needs room to move and settle as water fills the pool. If you anchor it too tightly, wrinkles will form and the liner may tear at stress points.

Do not refill too quickly. A fast stream of water can push the liner out of position and create large wrinkles that are hard to fix. Use a gentle flow and monitor the liner as it fills.

Frequently Asked Questions

How long does a pool liner usually last?

Most vinyl liners last 8 to 12 years with proper care. Liners exposed to direct sunlight, high chlorine levels, or rough handling wear out faster. Regular maintenance—keeping the pH balanced, brushing the walls, and avoiding sharp objects—extends the liner's life.

Can I patch a small hole in the old liner instead of replacing it?

Yes, if the hole is small (less than 1 inch) and the liner is otherwise in good condition. Pool patch kits are available at any pool supply store. However, if the liner is more than 8 years old or has multiple holes, replacement is usually more cost-effective than repeated patching.

What should I do with the old liner after I remove it?

Most municipalities accept vinyl pool liners in the trash, but check your local waste management rules first. Some recycling centers accept vinyl, though it is not commonly recycled. Cut the liner into smaller pieces to fit in your trash bins if needed.

Do I need to add chemicals after refilling?

Yes. Fresh water has no chlorine or pH balance. Once the pool is full, test the water and add chlorine, pH increaser or decreaser, and alkalinity increaser as needed to bring the water into balance. Most pool supply stores can test your water for free and recommend the exact chemicals you need.

Can I install a new liner without draining the pool completely?

No. The old liner must be removed completely, and the floor and walls must be cleaned. You cannot do either of these tasks with water in the pool. Partial draining will not work.