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20mil vs. 27 28 30 mil Swimming Pool Liners? Which is better?

Swimming Pool Liners

Over the years, the most common question customers ask is; which liner is better? A 20mil liner or a thicker liner such as a 27mil, 28mil, or 30mil? Over the years, I have spoken to many different liner manufacturers, pool builders, and retailers and most do not believe thickness is a factor in most cases. It is my recommendation that you choose your pool liner based off the pattern you like best.  I wouldn’t pass up your pattern of choice due to thickness.

So why would you choose a liner because of thickness?  Well, many professional builders actually prefer 20mil liners because they have more elasticity which helps them fit better in some cases. Thicker liners tend to be less pliable and much heavier which can make the installation more difficult. A proper fitting 20 mil liner will outlast an improper fitting thicker liner. There can be advantages to thicker liners though.  27mil and thicker liners can help protect against abrasive pool surfaces and provide additional puncture protection. Normally liners do not fail due to either issue, however, in some cases thickness can be an added benefit.

But won’t a thicker liner fade less over time? Why do liners fade? Good questions! From my experiences, liners fade or become “bleached” due to chemical erosion, sun fading, overstretching during the install process, and age. Over-chlorinating is the number one reason for a liner color fading. Just as excessive bleach will fade your clothes, over-chlorinating your pool will accelerate fading of a pool liner.  Any chlorine level above 3 PPM will accelerate fading.  To answer the first question, no, thicker liners will not provide any additonal protection against fading, because both 20mil and 30mil liners use the same clear coat protection layer.

To sum up the liner discussion, it is again my recommendation that you choose your pool liner based of the pattern you like best. If you don’t like your pool or the way it looks, it could lead to some of the problems I discussed! You want to enjoy your pool and the way it looks!  If you like your pool, you will take care of it!

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  1. Logan S says:

    If your liner’s going to fade away anyway, why worry about it fading a year or three sooner if it’s thinner? I agree that worrying about an appealing pattern is more important, chances are your pool is going to need some fixing up whenever the liner fades anyway. It helps if you’ve got the right maintenance knowledge as well.

  2. Troy says:

    Thank you for clearing this up for me! I’ve been looking into pools a lot lately, and was almost certain that a thicker liner would always be better, but now I see that it depends. for a pretty straight-forward installation, I think I can go with the thinner liner and be just fine- thanks!

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