How Do I Protect My Pool Liner From the Sun


The pool liner makes the pool, and one of the problems with outdoor pools is that they sit in the sun during the daytime. This can be an issue when you have a vinyl pool liner, as the sunlight can adversely impact the underlying liner and drive up your pool maintenance costs. However, having an indoor pool isn’t the only solution.

To protect your pool liner from the sun, you can use a pool cover during the day, have a shade over the area that receives more sunlight, avoid overusing the heat pump, and use a reinforced liner instead of a single-sheet variety. By doing so, you will limit the sun’s interaction with vinyl.

In this article, we dive deeper into the five tactics that help prevent sun damage in vinyl liners. These range from low-cost fixes to premium prevention methods. But before you learn more about keeping the sun from ruining your pool liner, let’s look at how the sun actually affects it.

How Does Sunlight Affect Pool Liners?

UV Rays From the Sun Can Bleach and Weaken Your Pool Liner

UV rays are harmless in short bursts, which is why we can afford to be outdoors for decent periods. However, persistent exposure to UV rays can cause skin health problems. It turns out human skin and vinyl liners have this in common: prolonged UV bombardment can have an adverse impact on both. While your pool liner might not get cancer from sunlight, it will get bleached and weakened with UV ray exposure.

Heat Can Cause Cracks in Your Pool Liner

Sunlight might have “light” in its nomenclature, but as far as most things are concerned, the sun is a bigger source of heat than light. With persistent sunlight exposure, a weakened vinyl liner can crack because of temperature changes that occur in the pool’s operation. 

Circulating water is cool, but whenever the filter pump is paused, the hot rays from the sun pump up the liner’s temperature. This contrast occurs on an almost daily basis which can test the flexibility of your pool liner. A few months of this can lead to surface-level cracks that only deepen with time.

Sunlight Can Accelerate the Impact of Chlorine

Chlorine can impact a pool liner’s health, and sunlight acts as a catalyst by providing the hot environment that speeds up the chemical reaction. You can prevent or at least minimize this from two sides: by either reducing the sunlight exposure or by decreasing the quantity of chlorine in your pool. 

Ideally, you should reduce both to the best possible practical point. And if you don’t control either factor, you’ll need to replace the liner much sooner than you would otherwise need to.

Five Ways to Protect Pool Liner From the Sun

Use a Swimming Pool Cover

Your swimming pool sits unused longer than it is used. And the most sun damage also happens during the period in which there’s no one in the pool. It goes without saying that using a simple pool cover can shield your vinyl liner from sunlight exposure. 

You can also adjust your swimming pool use times to make this protective measure go further. Simply use the pool during the evenings or at night. This way, your pool will not be without cover during moments when harsh sunlight can bombard the liner.

Build a Shade Over the Pool

Every house is built differently, and regardless of your pool’s position, you’ll notice that there is a part of your pool that gets more shade than the rest of it. This could be because of where your house is located or whether there are any plants close to the pool. 

It isn’t practical to have plants all around the pool to give it maximum shade, as having plants adds to the maintenance burden because of leaf shedding. It is much more practical to get a canopy-like shade that overarches the pool. The advantage of this method of liner protection is that it doesn’t constrain how often you use the pool or at what times. In contrast, a pool cover protects the pool only when the pool isn’t in use.

Plant Umbrellas Around the Pool Border

If you do not want to put up with the burden of raising a canopy to cover your pool and building an enclosure around your pool is out of the question, you can opt for a simpler solution: umbrellas. Though umbrellas will not cover the entirety of your swimming pool, they are great for covering the areas that the sunlight isn’t kind to. 

This tactic is best if your house already casts a shadow over the pool. Having the uncovered region covered with umbrellas is not only feasible but is also versatile as the umbrellas grant shade to those who rest beside the pool.

Use the Heat Pump Sparingly

One of the best ways of extending your pool liner’s lifespan has nothing to do with shadow, but it has everything to do with heat. When you use a heat pump sparingly, you keep the water temperature low. As covered above, the warmer the water, the more reactive the chemicals inside the pool. While sunlight speeds up chlorine’s reactivity and the consequent damage to the pool liner, colder water hinders this and largely preserves the vinyl liner.

Use a High-Quality Pool Liner

The best defense against vinyl liner deterioration might be to get a liner that is less likely to break down with prolonged exposure to the sun. While non-vinyl varieties can help, they come with their own drawbacks and price tags that might not make sense. It might make more fiscal sense for you to get a vinyl liner and have it replaced in two years than to invest in a concrete pool liner. But being confined to vinyl liner doesn’t mean you can’t upgrade it. 

Having your pool liner reinforced with polyester or even an extra layer of vinyl can help reduce the frequency at which the liner may require replacement. You can also look specifically for multiple layers instead of single-sheet liners.

Final Thoughts

Using a high-quality liner is the best way to avoid having to replace it. However, sunlight isn’t kind to any grade of vinyl liner, and you would be wiser to let your pool be exposed to the sun only when it absolutely has to be. To prevent sun damage, you should use a canopy and a pool cover alongside an aptly-timed pool schedule.

Jed Arnold

Jed spent every year from the ages of 15 - 22 as a Lifeguard (Red Cross) and ages of 17 - 22 as a Certified Pool Operator (CPO). Between working for over a dozen facilities and owning a pool, he carries over a decade of pool experience.

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