What Causes Wrinkles in an Inground Pool?

Low water pH may cause your inground pool liner to wrinkle, so test your pool's chemical levels weekly.Test Kit image by Cinneman from Fotolia.com

When building an inground pool, many homeowners opt for a vinyl-lined pool because it is more budget-friendly, smooth underfoot and typically has less chemical maintenance issues because of its non-porous surface. The main issue is wrinkles in the liner itself. The vinyl stretches smoothly across the pool, but from time to time, problems arise which cause the liner to pucker or crease. You can fix some of the issues yourself, but others may require the assistance of professional installers.

Improper Installation

In a new inground pool, one of the most common causes of wrinkles in the vinyl liner is improper installation. The liner may not be cut properly, so it does not fit the pool. Liners that are too large or too small may both cause wrinkling because they must be stretched or folded to fit the actual pool shape and size. Liners that are the wrong size or that are installed off-center may also cause the liner bead to come out of the track which loosens the entire liner, and wrinkles may occur in areas where the liner has come loose. One of the most important steps in vinyl pool liner installation is the use of a vacuum to remove any air between the liner and the floor material of the pool. Large wrinkles may form if this step is skipped or not performed properly, and there is no way to get rid of them without removing the liner and reinstalling it.

Another factor which may lead to wrinkles in your inground pool liner is improper water chemistry. A pool with water that is too acidic or corrosive may cause the liner to absorb more water, which stretches the vinyl and causes wrinkles. Check the pH of your water to make sure that it is not too low or acidic. Your vinyl-lined pool's pH may drop due to poor maintenance, so it is important to check the water's chemical levels at least two to three times a week to determine if any adjustments are needed. If tests reveal that your pH has begun to fall, add soda ash to the water to bring the pH back into the proper range. According to the North Carolina Department of Environment and Natural Resources, the pH of properly balanced pool water should fall between 7.4 and 7.6.

Draining your pool can cause serious issues for the liner as well. Vinyl liners must fit the size and shape of your inground pool, but they are typically cut slightly smaller than actual pool size and stretched to fit. Draining the water from a pool causes the liner to revert to its original, unstretched size. Liners that are more than a year old have typically lost much of their elasticity, so they will have trouble stretching back into place and wrinkles may result.