The first and most important thing that needs to be done correctly for a proper liner fit, is a good, accurate measurement. If you are not sure how to accurately measure your pool it is best to hire a professional. There are some people that measure pools for other pool professionals, because measurements are so important.
After you have provided all your measurements to your liner manufacturer, you wait for the liner to be made. When the liner is finished, it is now time to start the liner install process.
To begin the installation, remove the old liner, but before you can remove the old liner, the pool must be first emptied. This is a time consuming process, so in order to give you the most time on your installation day, I recommend to start emptying the pool a few days before your installation day. At S&R Pools, we do have many good pumps that can speed up this process, but even with high volume pumps it can take a few hours to empty 25,000-30,000 gallons of water out of a pool. Remove all the old faceplates, any gaskets that need to be changed and start cutting out the old liner(make sure you have plenty of heavy duty contractor trash bags, 3Mil thickness is best.) When removing the liner from the bead track, you should proceed with caution, if the wall foam falls down, it is very difficult to get it to stick back up to the walls.
Prep the pool floor and walls for the new liner. After the liner has been removed, it is time to prep the floor and walls before you can install the new liner. If you need to replace the wall foam, you will need 4 cans of spray glue (I use 3M High Strength 90) and a roll of wall foam. Spray the walls and the foam with the glue, wait a few seconds for the glue to become tacky, and stick the foam to the wall and rub it smooth. Move around the perimeter approx. 5′ at a time repeating the process of spraying the foam, the wall and attaching together. Once the wall is attached around the entire perimeter we need to go back and cut holes in the foam for the skimmers, returns, lights, and anything else around the perimeter that shouldn’t be covered by foam. You need to replace any of the cork gaskets, to make sure that there will not be any leaks at any of the skimmers, returns, or lights.
Finally it is time to set the liner. Depending on who your liner manufacture is, these next steps may be different. For reference I use Merlin liners, so all instructions will be assuming a Merlin liner. Take the liner and set it at the break line, there will be an arrow with the word deep on it stuck to the underside of the liner, point the arrow towards the deep end of the pool. Roll the liner out towards the walls, and pull the bead back to the shallow end. The liner will be marked on the back with the letters “BL” for the Break Line and will have “C” at the corners. After you attach the liner at the BL, next attach the shallow corners, and put a weight (I use water bags) on the shallow end to keep the liner from moving towards the deep end when you attach the deep end corners. Attach the deep end corners at the “C” and then attach the rest of the walls, be careful not to pull too hard if it is a hot day, because you can stretch the bead and end up with a big bunch of bead without anywhere to put it.
With all the bead in the liner track (leave a small space open for your vacuum,) now is time to put your vac in and remove all the wrinkles. Put your vacuum hose behind the liner, and turn it on. While the liner is sucking out the wrinkles you want to push the liner into all the areas where there are air pockets behind the liner and remove material from the places with wrinkles. A good vacuum should be able to pull the liner back against the wall and hold it in place during the filling process.
Fill the pool! Fill the pool up to about 4″ deep in the shallow end. At this time you should have enough water pressure over the entire pool floor to be able to turn off the vacuum and pull it out, attach the last section of bead. check the entire floor to make sure that there are no wrinkles on it, if you see a wrinkle after there is more than 6″ of water it will be hard to remove it, and after there is 3′-0″ of water it will be almost impossible to remove any wrinkles.