Long-Lasting Skylights: Look for UV Protection and a Warranty to Substantiate Manufacturers’ Claims


In a warehouse I recently visited in Texas, I noticed skylights that were amber in color and barely letting in any light. This is a common issue with older skylights. The problem originates from using inappropriate materials that can’t withstand the harmful effects of UV light. UV light doesn’t only cause sunburn; it also degrades fabric, carpet, wall paint and virtually everything else exposed to it for prolonged periods of time — including skylight domes. Walk into any 20 – 30 year old building with skylights and look up. Odds are high that the skylights will be yellow or even brown in color, resulting in poor lighting performance. Why is this and can it be prevented?

An Informed Buyer Will Find Out The Material Used For The Outer Dome

It’s safe to say that no one wants a yellow or brown skylight, but many consumers don’t know how to predict which units will age gracefully and which ones will discolor badly over time.

The first aspect an informed buyer should examine is the type of material used for the outer dome. The outer dome is what sees the harshest conditions, including the most UV light exposure, the largest temperature swings, and the effects of water.

Polycarbonate: Choose UV Grade Polycarbonate With Extended Warranties

If polycarbonate is used for the outer dome, be aware that at the time of this writing (2015) the major polycarbonate sheet manufacturers will warranty their material for ten years, and that is only if a UV protected grade of polycarbonate is purchased. Non-UV protected grades of polycarbonate are less expensive but will yellow noticeably in 5 years. Check the warranty, and if the warranty duration is less than 10 years, this is a red warning flag that the skylight manufacturer might be cutting corners and using a less expensive grade that will turn yellow or brown in 5-10 years, after their short-term warranty expires.

Acrylic: Choose Impact Modified Acrylic With Superior UV Protection

If acrylic is used for the outer dome, find out if the acrylic is impact modified or not, and ask about the warranty on the dome. Standard grades of acrylic do not contain impact modifiers. While acrylic is inherently much more UV stable than polycarbonate, it is also more brittle and more susceptible to the effects of moisture.

A properly formed acrylic dome fabricated from good quality acrylic from a major manufacturer should last 15 years with acceptable yellowing performance. However, if it lacks impact modifiers it will be vulnerable to cracking and crazing from stress and chemical attack. Once again, an informed buyer will ask the manufacturer what their dome warranty covers and for how long. If it is only a few years, then this is a red caution flag that the manufacturer might be using less expensive materials lacking impact modifiers and/or lacking the best UV protection package.

For maximum longevity and minimal yellowing, seek a dome made with impact modified acrylic and containing a superior UV protection package. Such materials will carry a 30 year warranty on minimal yellowing. The impact modified acrylic will be much less susceptible to cracking or crazing, although it will never match the impact strength of polycarbonate and therefore is not often used in hurricane-prone areas such as South Florida.

The Benefits Of Using Superior Quality UV-Protected Materials

The UV protection package has the added benefit of filtering out UV light, while allowing visible light to pass through. This means that the outer dome will act like SPF 100 sunscreen, enabling the rest of the system to last much longer since the rest of the system will not experience the harmful effects of UV light exposure.

Furthermore, with no UV light transmission, such skylights can be used with no fear of degrading carpet, furniture, graphics, artwork, or anything inside the building. Not only will the skylight age gracefully, but so will everything inside the building as well, hopefully including the humans.

Connect With Us

11 Mount Vernon Avenue
Mount Vernon, OH 43050 
1-800-886-8847 (U.S.A Only)



Want More Information on Replex Products?

Whether it's a transportation mirror, safety mirror, plastic dome, or custom product, we're happy to answer all your questions.



Replex Reads

Sign up for our monthly Newsletter and receive the latest updates from our facility floor!