A guide to installing a replacement overlap pool liner in a level-bottom above ground swimming pool. While there are several methods that can be attempted, this seems to be the easiest and least-risk method. We also have a couple of pre-job tips. Screws in top-rails and plates may be rusty. Have a can of WD-40 on hand to loosen them up. Also, wasps LOVE to hide under top rails. Cautiously eliminate the wasps with your favorite wasp spray.

Only install flat bottom pool liners in sunny, 75 degree plus, weather. Only install dished or expandable pool liners in sunny, 85 degree plus weather. Only fill pools during daytime hours. Check your overlap pool liner and pool frequently as pool fills with water. Completely inspect the pool liner before starting installation. Once you start to install it, you own it, including all defects.

  1. Drain your old pool. Remember that once the water is gone, your pool is susceptible to high winds. If your pool is into the ground more than a few inches, stay away from the pool as much as possible so that you do not cave in the dirt and push the wall in.

  2. Without removing any rails, cut the old pool liner out. There will be a thin strip of pool liner left at the top of the wall extending over the top of the wall. This will be removed at a later point.

  3. Address the bottom of the pool. Remove any roots, rocks, or sharp objects that could puncture the new pool liner. Put down new replacement sand or vermiculite if needed. Make sure the cove around the inside of the pool wall is firm, stable, and in good condition. If it has compressed or washed out over the years, re-build. Most manufacturers recommend a six inch high cove.

  4. Make sure skimmer and return holes are in good shape. Any areas of rust should be gently sanded and painted with a specialty rust preventative. Make sure the sanded residue does not mix into the ground inside the pool.

  5. Carefully open the new pool liner box. DO NOT USE A KNIFE OR OTHER SHARP OBJECT!! Be sure the pool liner is the proper size to fit your pool. There are no returns for a pool liner if the box has been opened. If possible, unfold the pool liner in your yard. Make sure there is nothing there that would puncture it. If necessary, you may unfold the liner inside the pool. Once unfolded, roll the pool liner length-ways, and then fold it in half. With help, carefully lift the liner over the wall and place it inside the pool.

  6. Remove shoes and make sure your toenails and fingernails are well trimmed.

  7. With one other person inside the pool, unroll the liner and position into place. Use the seam that connects the pool liner's sidewall and bottom as a guide, keeping the seam equal distance from the wall. There may be a little variation if the pool is slightly out of shape. Most pools are slightly out of shape. But remember that once you put a lot of water on the pool liner, it is not going to move.

  8. Smooth the overlap pool liner out as much as possible.

  9. Remove any three consecutive sections of top-rail and then the coping and old liner remnants.

  10. Using the old plastic coping or spring-style clothespins, put the liner over the wall a few inches and secure. Do not worry if the sides of the liner are loose. Be careful not to snag the liner on the edges of the top rails.

  11. Skip a few sections and repeat step number 10. Continue until the liner is over the wall throughout the entire pool. Some top rails will still be on the pool and the liner will not be over the wall at these points. This is okay. If you like, you may place a protective layer of duct tape over the edges of the top rails that are still remaining on the pool.

  12. Gently smooth the liner out to minimize wrinkles, and then begin running water SLOWLY.

  13. As the water is added, with your bare feet and hands, gently scoot the liner wrinkles out, working in a straight line from the center to the edges. A little practice will make you an expert. If the water is coming in so fast that the liner becomes difficult to move, shut the water off. Remember that in a 24' diameter pool, an inch of water weighs more than one ton!

  14. As needed, take excess liner over the wall.

  15. When there is six inches of water in the pool, the liner is ready to be put in its final position on the sidewalls. Gently place your foot at the bottom to hold the liner in place, and then pull any excess liner over the wall. Use the plastic coping to secure the liner into its final position. Continue around the pool, removing rails that are still on the pool. If you have wrinkles in the side, work them out now, as they will be permanent if you do not. In some cases where the pool is not perfectly round or oval, you will not be able to avoid wrinkles in the sidewall. If your pool has a metal stabilizer bar, place this over the coping as you complete positioning of the liner. As you move around the pool, replace top rails on the pool. Complete the entire pool.

  16. When the water level has risen to just below the skimmer and return you will now bolt on the skimmer and return. Do NOT cut the skimmer liner hole until the skimmer is attached. It is HIGHLY RECOMMENDED that you replace skimmer and return gaskets before placing the skimmer and return back on the pool. Once the entire assembly is attached, VERY CAREFULLY cut the liner out INSIDE the faceplate. Use a very sharp pocketknife or razor knife. As for the return, you may need to cut out the liner BEFORE attaching the return. If so, carefully cut out the liner with a sharp pocketknife or razor knife. Take your time and keep the cut round. If your cut is too big to be covered by the return gasket, the pool will leak.

  17. Continue to fill and check for leaks at the skimmer and return. If necessary, gently tighten the two to eliminate any leaks.