A crease in a liner is where you have a fold of the PVC material that is large enough to sit back on itself creating three layers. It is best to avoid this and while it normally does not affect the function of the liner, it can reduce the life of the liner if the crease is on the floor of the pool in a location where cleaning equipment or an automatic cleaner could catch on it. Often when a pool liner is poorly installed, there are creases left in the liner. The goal of all liner installations is to have no creases that are folds of PVC.
Sometimes there are “packaging wrinkles” showing in the liner where it has been folded in the box and stored for a period of time. Provided these are not actually folds of material, they will generally disappear in time and can sometimes be dispersed using a “bare foot” and gently doing a twisting action on them.
Other small creases can be located in an area where there are steps or corner of the pool. These locations have less water pressure on them and so it is more difficult to fit the liner here. At times, small folds will be left in these corners as there is nowhere else for the material to go. Provided these do no interfere with the function of an automatic cleaner, then they are generally acceptable and do not impede the daily function of the pool liner.
The are a number of causes of large wrinkles in the floor or wall of the pool liner:
- The pool wall has been modified and trimmed down in length. Some people will trim a pool wall if it appears too long when erecting it, instead of adjusting the position of the base rails to the correct size.
- Commonly the wrong size liner ordered for your pool.
- Not knowing the brand and exact model of the pool and using a generic size liner that may not be fully compatible.
- Or, the liner installer has not taken sufficient time to position the liner correctly in the pool and the result ids the liner is tight in some areas and loose with wrinkles in other areas.
You can usually see for yourself if the liner is not positioned correctly, by checking the position of the liner wall/floor seam in the pool. The seam generally should be located about the same distance from the wall of the pool at each end and each side, unless the pool has a deep end. With a deep end, the seam will generally be a little further away from the wall of the pool in and around the deep end, due to the extra stretch required for a liner to fit a deep end style pool.
If you are installing the liner and there are obvious wrinkles or creases in the liner, don’t continue to fill the pool as once full, the creases will be permanent, they do not disappear by themselves when the pool is full of water. To remove them, you need to drain the pool and re-position and adjust the liner. Then fill the pool once you are happy there are no major creases in pool.