UV Ray Exposure to Roof Membrane: Protecting Your Investment
August 1, 2023 Jessica Campbell
Our roofs are the very first line of defense against the natural elements, shielding us from rain, wind, hail, and snow. However, many people may not realize that even the sun, and the UV radiation it emits, can wreak havoc on their roofs. UV radiation can cause significant damage to various roofing materials, leading to costly repairs or premature replacements. In this article, we will explore the impact of UV rays on different roofing materials and how to prevent and fix issues caused by sun exposure.
UV radiation can harm asphalt shingles by getting right down to the chemical compounds and altering them. The oxygen mixes with the hydrocarbons, which causes the coating of the shingles to break down. As the material breaks down, the oily substance covering the shingles evaporates, which leaves the shingles unprotected. They then become dry and start cracking. Heat can also play a part, as it encourages expansion, followed by contraction when it cools at night, which causes even more cracking. This is called thermal shock, and as it continues throughout the years, the very structure of the roof can degrade.
Granule loss in a roof membrane can occur due to various factors, and it can lead to significant issues if left unaddressed. Most commonly seen in asphalt shingle roofs, granules are the small, coarse, and colored particles that provide protection and weather resistance to the roofing material. Over time, exposure to the elements, weathering, foot traffic, and natural aging can cause these granules to become dislodged and accumulate in gutters and downspouts, or simply wear away.
Granule loss is a concern because these granules play a vital role in protecting the underlying roofing material from harmful ultraviolet (UV) rays and extreme weather conditions. Without the granules, the roof’s surface becomes vulnerable to rapid deterioration, increased UV exposure, and accelerated aging, leading to potential leaks, cracks, and reduced overall lifespan of the roof.
When granule loss is noticed on a roof, it is crucial to act promptly. Roof renewal or restoration is a viable solution to address this issue. This process involves hiring a qualified roofing professional to apply a protective coating and new granule layer to the affected roof surface.
UV ray exposure can also cause blistering. Blisters form when there are pockets of air or moisture trapped between layers of the roof’s membrane or between the membrane and the roof deck. As the sun heats the roof, those pockets expand and stretch the membrane. In severe cases, the membrane will crack when the pressure becomes too great. Even if the roof membrane doesn’t crack, blisters are usually a cyclical problem. That is, once they form, the membrane stretches permanently, which allows for even more air or moisture to infiltrate the membrane layers. This causes even more expansion. Each time the sun heats your roof, there is the potential for the blisters to grow a little larger.
Blistering can still occur on a well-installed roof system. If blisters do not indicate severe damage, it is generally advised to leave them undisturbed. However, it is crucial to routinely inspect observed blisters, as there are situations where repairing them becomes necessary to prevent potential complications like bursting.
To repair a blister, technicians cut away the membrane until they reach an area where the membrane still adheres to the roof tightly. They then apply new compatible membrane materials over the blistered area, making sure the new membrane extends at least six inches around the edges of the blister to ensure that your patch remains leak-proof despite the expansion and contraction caused by temperature shifts. Alternatively, on a bitumen roof, the technician may be able to cut an “X” into the blister and then peel back the loose membrane layers, fill the void underneath the membrane with bitumen and pressing the membrane back into place.
Regardless of the repair method chosen, it is crucial to have a qualified roofing technician handle the blister repair work. The repair process involves cutting into the roof membrane, which can be invasive. If this is not done correctly, it may compromise the integrity of the roof system at those areas, leading to potential openings for water to seep in and causing even more problems than it solves. Even though a blister on the roof might cause concern, it’s crucial to wait for a qualified professional following industry and manufacture standards to handle the repair, ensuring the problem is addressed properly and effectively.
Alligatoring is a sign that your roof is aging. The sun’s UV rays dry and damage the roof’s surface, and after three to five years, the coating may develop small cracks. If left untended, the problem will get worse. Ice, sunlight, and the heating and cooling shifts between day and night will all cause new cracks to appear while widening the existing cracks. Repairs for alligatoring on the roof membrane can vary depending on the severity of damages.
Roof sealants are essential to the overall lifespan of a roof. These coatings provide extra protection against damaging elements such as snow, ice, or rain. However, powerful UV radiation can compromise the integrity of your roof sealants over time. Whether it be caulking or sealant at penetrations, heat energy from the sun breaks down the chemicals in seam sealants and prevents them from doing their job effectively. Annual renewal or review of these sealants is important to ensure that no openings have formed allowing for potential water ingress.
Darker rooftops are vulnerable to a type of bleaching. This bleaching effect can affect the color of the material, either fading it out or turning it completely white. While bleaching is a cosmetic problem and not a structural problem, it can leave your roof looking unsightly. Wood shake roofing and architectural shingles are the most vulnerable to bleaching however, this occurs at varying levels on all roof systems.
Metal roofing suffers in extreme heat. Concentrated UV rays create a drastic change in the metal’s temperature – an effect known as thermal shock. This type of sun damage causes the metal to destabilize, thinning out the metal and resulting in cracks. These cracks create the perfect entryway for moisture, which can lead to moss growth, a roof leak, or the support underneath the metal roof to rot.
Amidst our focus on protecting our buildings from rain, wind, and snow, we often overlook the silent culprit that can wreak havoc on our roofs – the sun’s UV rays during hot weather. UV radiation causes substantial damage to various roofing materials, leading to issues such as granule loss, alligatoring, blistering, and bleaching. To prevent costly repairs and premature replacements, it is crucial to take proactive measures, such as applying new coatings, renewing sealants, and conducting regular roof maintenance. By safeguarding our roofs from the damaging effects of UV rays, we can ensure their longevity and optimal performance, ultimately protecting our homes and buildings from the elements and preserving their value for years to come.