5 Effects of UV Rays on Unprotected Roofs

Brad GordonUnprotected Roof

A safe well structured roof can protected your home away from UV rays

When we think about the things our roof protects us from, the common answers we come up with are usually rain, snow, wind and hot sunlight. For the most part, people are well aware of the hazards that significant precipitation and wind can wreak on a roof. Loosened shingles and sudden leaks are issues that we are all familiar with. What people may not realize is how damaging the sun can be on a roof as well. The ultraviolet rays that are given off by the sun can affect your roof integrity on a chemical level. Over time, the sun will be the biggest issue faced by an unprotected roof.

How Does UV Rays Affect Your Unprotected Roof?

1. Deterioration

A typical asphalt shingle roof can last for decades if it is properly cared for. Keeping the roof clean and free of dirt and debris is always a good idea, as this will help maintain the protective coating that blocks the sun. In cases where the roof protection is no longer present, the sun will cause shingles to deteriorate in the following noticeable ways.


2. Loose Granules

A standard asphalt shingle consists of three separate layers. The top layer consists of those coloured granules that give the roof its appearance and protection. When the roof protection fades off, granules will begin to loosen and run off the roof. Eventually the shingles will be bear in some spots, leaving the roof open to all kinds of additional damage.


3. Fading

Ever notice how things that are left out in the sun start to fade in colour? That is because UV rays actually have a bleaching effect on solid objects. Roof shingles are no exception to this, and those which contain pigments such as slate shingles can be susceptible to premature fading without proper roof protection.


4. Rapid Aging

Without adequate roof protection, you can’t expect to get the most in terms of durability and life span out of any type of shingle. Asphalt shingles will curl and crack, as will cedar shake.


5. Chemical Changes

As we previously mentioned, UV rays can cause damage to tiles on a chemical level. The radiation from the sun actually breaks down protective roof membranes on a chemical level, which leads to shrinking and cracking after the shingle is exposed to oxygen. To avoid this issue, additional solar protection can be added to a roof for extra protection. Many of these sealants are available for an additional cost upon installation, but they can also be added down the road.


Once these chemical changes occur, your shingles will be more susceptible to damage caused by temperature changes as well. As the sun heats the unprotected shingles, they will expand in size. Once the sun sets, the shingles will shrink and crack. This means they will eventually lose any water-resistant properties, and you may have to deal with more leaks in your roof.



Since there is no way to really escape the sun’s rays down here on earth, there are some measures we will have to take to keep our roofs intact. Having regular roof inspections performed on an annual basis will help you stay on top of any potential problems before they occur. You can also opt for a different, more durable roofing material when the time comes for a replacement. Certain rubber membranes and metal roofing materials are impervious to the long term effects of UV radiation. In addition, these roofs already last decades longer than their traditional asphalt shingle counterparts. A good roofing contractor will be able to offer you these options if you make the inquiry.


For more information about how to improve the lifespan and performance of your residential or commercial roof get in touch with Coast Mountain Roof today. You can also arrange a free estimate for your next roofing project by getting in touch via phone or email.