Unfortunately this happens due to the hydro static pressure that is around the swimming pool structure, forcing the liner to "bubble" or "float". Now this typically does happen when there is a lot of groundwater in the earth around the pool. Usually caused by high amounts of rain or even the fact that you may live in a lower area than the rest of the homes in your neighborhood. It is almost always an issue in homes that are marked "flood zone". As the pressure goes back down the liner will go with it and it is possible that it will not go back into place 100% and cause a wrinkle of some sort.
Prevention: Unfortunately due to the construction of a vinyl liner pool there isnt really a way to prevent this problem from happening. Many pool contractors will install a "drain tile around "shelf," for vinyl liner purposes, the depth of the shallow end all the way around the pool of the pool to help relieve hydro static pressure. To tell you the truth and from experience, it will not do the trick unless you can run the drain tile out to lower land. Water is self levening, so if your backyard is rather flat, you will never have enough space to run out the pipe to low enough ground.
You will want to make sure that your pool contractor installs some sort of "de-watering" system or "dry-pit." For example a dry pit on swimming pools, is very similar to a sump pit in the basement of a home. The sump pipe goes down to the lowest point possible of the swimming pool. As water gathers you will be able to look down the sump pipe to see how much water is around the pool. If water is visible, you can now drop a pump in the hole to remove the water. Thus helping to alleviate the hydro static pressure. It is also possible to install an automatic pump that turns on and off by itself with a flotation mechanism. This is so you do not have to constantly keep looking down the pipe for water. Once the float is activated the pump will automatically remove the water. If you do choose this route of installing an automatic pump it is important to make sure you always have power. Just like a sump pump in a basement.
As I mentioned in the last section, liners may wrinkle simply due to the water pressure in the ground around the pool. Another common issue we see with wrinkling is due to the abuse of chlorine and other chemicals that tend to have a lower pH. The chemicals pull the moisture inhibitors out of the vinyl and force it to shrivel up. This is a very similar process of dry skin! ;) The problem with wrinkles in the liner is not just the fact that they look bad, but it also leaves and opportunity for dirt to collect at the crease, ehich inturn makes it very dificult vacuum the pool floor.
Prevention: Chemical wrinkles are impossible to stop 100%. In particularly if you are fortunate enough to have a long life expectancy of your liner it will happen.
Due to the chemical make-up of the vinyl liner material, the instant chemicals hit the liner, it is a natural process for the vinyl to loose its moisture inhibitors, making become more dry and eventually will wrinkle. We have seen this happen in as little as 1 year but also have seen 7 to 8 year old liners be wrinkle free. The most important thing to remeber here is do not abuse your chemicals. Keep chlorine levels in check and pH levels in check, and you are giving yourself the best shot for a wrinkle free vinyl liner!
Its obvious that all swimming pools need to treated with chemicals. For the most part, as I stated earlier, if you make sure to keep the pool water balanced you should not have to many surface issues until later down the road. When you do get later on down the road, as with wrinkling, it is inevitable that you will start to notice that your liner will begin to fade or bleach out." This is typically due to the fact that the chemicals have taken its toll on the printed pattern on the liner. The liner will begin to fade and even yellow in some spots due to staining.
Prevention: I know I probably sound repetitive and its getting mundane, but it has to be said :) Watch the the balance of the pool water. It is probably the number one most important thing about a vinyl liner.
When designing a vinyl liner pool, it is important to understand that most companies start there base package with a thermo plastic stair case. What makes these stairs great is that they are priced very well to keep pool costs low. The unfortunate thing is that some customers think they may look a little lower quality, which is obviously just an opinion. More importantly, these stairs will start of whhite but can eventually yellow or even possibly turn orange colored. Typically this problem is due to metals in the water, such as iron or even copper, that attach to the surface. If its not taken care of immediately, it does get more dificult to remove the staining and sometimes impossible.
Prevention: One of the more popular things to do is to upgrade the swimming pool staircase to a more custom looking, vinyl finished stair. Now this still does not solve the problem of why they would stain. It just helps the face that you would not have to look at yellow or orange stairs. Truth be told the liner could actually stain, but in my experience that is much less likely to happen than a yellowing stair. The main prevention of this problem is to make sure that you keep metals such as iron and copper out of the water as best as possible. Using a metal sequestering agent or a flocculant will help greatly with the prevention of this problem.
Well this one can be a pretty obvious one, but even though its obvious its still a top 5 problem. Liners can be expensive typically ranging from $3,000.00 - $5,000.00 depending on the size of the pool and how custom the pool needs to be.
Prevention: Unfortunatley you will not be able to prevent this. Its only a matter of time before you will have to replace your liner.
Well there you have it guys, the top 5 problems with a vinyl liner swimming pools. Like I said earlier, all swimming pools have pros and cons, I just think to help you as the customer, sometimes its just as important to know the negatives of product as it is the positives. I hope this has been some informative enough to answer some of your new pool buying questions!