How to Repair a Swimming Pool Vinyl Liner

Boil It!

Boil a kettle of water. It may take several kettles, depending on the size of your liner. Slowly pour the hot water directly on the sagging vinyl below the top edge. Use a kettle or can with a long spout, such as a watering can. Do not pour onto the very top edge of the vinyl, but just below the top, because you next have to grasp that top edge. Pour slowly back and forth across the vinyl.

Pull the vinyl up. As the hot water softens the vinyl, grasp the top edge and firmly pull the vinyl up and above the track, so that when released it remains just above the track. It may take several cans of water before you can pull the entire edge up sufficiently. It may also be necessary to lower the water level 6 inches (15.2 cm) or so to increase the amount of vinyl you can stretch. This task is easier if one person pulls up while the other pours the hot water. But one person can do the job alone if necessary.

Re-track the vinyl. Starting on one end, firmly twist the top edge horizontally and push it into the metal track. The top underside of the vinyl has a V shaped groove which should slip into a similar V groove in the top metal track. You should feel the edge of vinyl slip into the groove, which is supposed to keep it in place.

Hold the vinyl in place. Use a large, wooden paint stirrer to help push and hold the vinyl in the track as you pull the vinyl up and into place. Be very careful not to tear through the vinyl. For longer splits use wooden clothes-pegs broken in half and placed along the split every few inches.

Finish up. Upon completion of stretching and tucking, get several special short (1/4 to 1/2 inch long) plastic jamming pieces from your pool supply store, and jam them into place between the top of the plastic and the underside of the metal pool rim. This will help ensure the plastic liner stays in place.

Blow Dry It

Use an extension cord and a hair dryer or heat gun. Heat an area of the liner to stretch by holding the blow dryer a couple of inches from the surface and at an angle. Keep the dryer moving so you don't burn the liner. You don't need to superheat the liner—just get it warm enough to make it pliable.

Put the liner back in the track. Done.

Note: Be careful that no one is in the pool while using electrical appliances, as dropping it in the water could be deadly.