Asphalt shingles are meant to resist a variety of weather conditions, but continuous exposure to summer heat can wear down even the most durable roofing materials. Understanding how high temperatures impact asphalt shingles can help homeowners avoid early roof damage and expensive repairs.
Here are a few ways that heat affects shingles:
- Wear and Tear on the Roofing System: During the summer, roof surfaces can get substantially hotter than the ambient air temperature. On especially bright days, asphalt shingles can achieve temperatures above 60°C. As shingles absorb heat and ultraviolet (UV) rays, they naturally expand. When temperatures drop in the evening, the materials contract. Over time, this repeated cycle of expansion and contraction can contribute to wear and tear on the roofing system.
- Premature Aging: Another common side effect of extreme heat is premature aging. UV rays progressively wear away the protective oils in asphalt shingles, making them brittle and less flexible. As shingles age, they can develop cracks, curled edges, or other indicators of deterioration, jeopardizing their capacity to protect the home from moisture.
- Granule Loss: Heat can also affect the granules that coat the surface of asphalt shingles. These granules protect the roof from UV damage and increase longevity. Over time, high sunlight can cause granule loss, making shingles more susceptible to weather-related deterioration.
Reduced Ventilation: Proper attic ventilation is essential in preventing heat-related roofing concerns. A well-ventilated attic regulates temperatures by decreasing heat buildup beneath the roof deck and relieving stress on roofing materials. Excessive heat, without appropriate ventilation, can reduce the lifespan of asphalt shingles and raise cooling costs within the home.