22/10/2015Pool Liners – The Standard
The standard thickness for an in-ground vinyl liner is 20mil. It has been the standard for many years. Thicker, 27mil material, was available as an alternative. It was used mainly in climates that experienced extreme cold, where the ground becomes frozen. Because of this, thicker liner material developed a reputation for being more durable. Is this reputation earned? Does thicker material make a better liner? If you look closely you may find the answer is, no.
First, consider what happens when a pool liner is manufactured, using thicker material. The liner becomes a much heavier and stiffer product to work with. When it is installed it is more difficult to move and adjust. A stiffer liner will not conform to the shape of the pool as well. Over time a stiffer heavier liner begins to pull away from the wall in teh corners. This is one of teh main factors that causes liners to fail. When the liner is pulled out from the wall, it is under greater tension. At teh same time, it is exposed to more direct sunlight. The UV rays leach the plasticizers from the material, making it more brittle. This will increase the chance the liner will tear.
Second, many believe that a thicker liner will resist puncture better. This is not really the case. A standard 20mil liner is a strong durable product that will resist puncture well. If an object is sharp enough of applied with enough force to penetrate a 20mil liner it would probably penetrate a 27mil liner, too.
Third, there is a belief that a thicker liner will last longer. However, there 2 main reasons a pool liner has to be replaced, because it tears or because the colors fade. Thickness will not prevent either of these. The chemical composition of the liner is the same, regardless of the thickness. Over a long period of time, the sun and chemicals will breakdown the liner. This is also true when it comes to fading. A 27mil liner will fade at the same rate as a 20mil liner. Therefore, just because a liner is thicker there is no proof it will last longer.
There are multiple reasons why 20mil became the industry standard for in-ground vinyl pool liners. A 20mil liner has the right balance of durability and flexibility. It creates a liner that can be handled without undue stress and difficulty. When it is installed it conforms well to the shape of the pool. Thicker, 27mil material, does not have any significant benefits over 20mil. In teh end, the best way to extend the life of any liner is by maintaining a good chemical balance and covering it with a safety cover, when not in use.