Does UV Radiation Cause Roof Damage?

UV Roof Damage

Can UV radiation cause premature degradation of a roof? Sadly, roofs bear the brunt of all weather systems, including rain, snow, hail and wind. But one of the often-overlooked causes of roof damage is the level of exposure to ultraviolet rays from the sun. In climates with lengthy sun exposure at varying times of the year, UV radiation can cause asphalt shingles to break down much faster than a homeowner would like. How do the sun’s rays affect your roof and what can you do to prevent the need for early replacement?

UV Radiation’s Effect on Asphalt

Even on cloudy days, UV radiation affects the physical state of asphalt shingles by altering its chemical makeup. Oxygen molecules combine with hydrocarbons, contributing to the beginning of material breakdown. As these molecular changes take place, the oily moisture of the material evaporates, leaving the shingles brittle and prone to cracking.

It is not only the simple exposure to ultraviolet rays that degrades shingles, but the heat involved, triggering the expansion and contraction that further wears on the asphalt. When the material heats up, it expands. At night, once the heat source has disappeared, the roof shrinks back to its original state. This process is known as thermal shock, and over time, the repetitive cycle creates weaknesses in the roof’s structure. Additionally, the metal gutters and flashing connected to the roof undergo thermal shock, but they expand and contract at different levels. Gradually, the mismatch of the expansion and contraction can cause these components to pull away from the asphalt shingles, necessitating immediate repairs to avoid water damage.

UV-Resistant Roofing Material

While asphalt shingles are the most common choice of roofing materials, homeowners who live in hot, dry climates and want to invest in a roof that will withstand UV rays better than traditional asphalt have multiple options. One of the top choices is metal. While metal still is prone to a certain level of thermal shock, UV radiation does not change the material on a molecular level. In addition, EPDM rubber membrane roofing systems are also an alternative choice for property owners interested in a long-term roofing installation with few negative side effects from significant UV ray exposure.

Strategies for Long-Term Roof Maintenance

The primary reason asphalt shingles are coated in granules is to limit the UV ray exposure to the asphalt underneath. Due to heavy precipitation and general wear and tear, these granules fall off over time, placing the shingle at a higher risk of expedited degradation due to UV radiation. Conduct an annual inspection of your roof and contact a professional to make repairs as soon as you notice roof or water damage, either interior or exterior. Homeowners should regularly check their gutters and downspouts for signs of increased granule discharge. View the shingle coverage from the ground and make note of all shingles with a significant granule loss.

Contact Knockout Roofing for additional information on how you can protect your roof from the harmful effects of UV radiation and preserve your investment for years to come.