What is roller burn and why does it happen?

Roller burn occurs when a pool cover is stored on the roller without using the protective overcover, or when an old or deteriorated overcover no longer blocks UV effectively.

Solar pool covers are designed to allow sunlight to pass through when floating on the water to help heat the pool. However, when the cover is rolled up onto a roller, multiple layers of material are stacked together. Without protection, the sun’s UV rays pass through and intensify between these layers, creating a magnifying effect.

This buildup of heat and UV exposure can cause the material (LDPE) to overheat and shrink, leading to deterioration in the form of horizontal “burn” lines across the cover. This is permanent damage and will significantly reduce the lifespan of the cover.

Even short periods of sun exposure can contribute to roller burn. Regularly leaving the cover unprotected on the roller — even just while swimming or cleaning — can gradually weaken the material over time.

To prevent roller burn, always use a protective overcover whenever the pool cover is stored on the roller, even if only for a few minutes.

What does roller burn look like?
You will typically see distinct horizontal lines across the pool cover, which align with the top of the roller when the cover is rolled up. These lines indicate areas where overheating has occurred within the layered material.

In these affected areas, the cover can begin to shrink across its width. This happens because overheating softens the plastic and causes the air inside the bubbles to expand, stretching the material. Over time, this leads to permanent distortion and uneven shrinkage of the cover.

Overheating occurs when the cover is off the pool, folded or rolled, and exposed to direct or partial sunlight. Heat builds up between the layers, the material becomes more malleable, and the bubbles stretch from their normal flat profile to a convex shape — resulting in abnormal shrinkage.

It’s important to note that leaving a cover under shade cloth or a patio does not provide adequate protection from UV exposure. The cover must be stored in complete shade, with a protective overcover in place.

Covers affected by overheating will continue to function to some degree; however, reduced lifespan and performance should be expected, and this type of damage is not covered under warranty.