Heat takes a toll on roofing materials, especially after summers like this one, where regions across the US and the world experienced long stretches of intense sun and high temperatures. From material expansion to UV exposure and the effects of humidity, it’s a good time to look for accelerated wear or exposed problems that need attention as we glide into autumn and winter.
The Effects of Sun and High Temperatures on Your Roof
Your roof surface can become much hotter than the outdoor air on a sunny summer day. Repeated temperature swings put materials through cycles of expansion and contraction, while months of UV exposure add another source of wear. “Extreme temperatures can put roofing materials under significant stress,” shared Alex Morrisey, a roofing specialist at Best Roofers. “Homeowners may see cracked roof tiles, warped materials, or softened and blistered membranes on flat roofs.”
How a roof responds to heat depends on more than the material covering it. Color, ventilation, insulation, underlayment, installation, and the overall roof design all play a part in how your home responds to heat and sunlight.
"Conventional dark asphalt shingles are typically the most susceptible to heat-related degradation; however, roof performance depends on a wide range of factors,” explained John Moore, Sr. Product Manager Roofing at CertainTeed as he listed the above determinants. “In many cases, those system-level variables can be just as important as the roofing material itself."
If you're not sure how hot (or cold!) your attic actually gets, get yourself a thermal camera that plugs into your smartphone. We've tested several over the years, but one of the newest models—RISION Magic or Magic Pro—work with both Android and iOS, and make it easy for homeowners and professionals alike to monitor temperatures and simplify maintenance checks.
How to Check for Changes in Your Roofing
A post-summer inspection doesn't have to mean climbing onto the roof. From the ground, you might be able to spot obvious changes.
Check for:
- Cracked, curled, or warped shingles or tiles
- Missing or loose roofing materials
- Areas where asphalt shingles have lost a lot of granules
- Cracked or blistered areas on a flat roof membrane
- Damaged flashing around vents, chimneys, or other roof openings
- Signs of leaks inside the attic or upper floors
Unaddressed, these types of damage can have a compounding effect. “Existing roof damage can make a roofing system more vulnerable to extreme heat,” noted Moore. “Issues such as cracking, granule loss, curling shingles, and deteriorated underlayment reduce a roof's ability to withstand prolonged UV exposure and thermal cycling, often accelerating further deterioration during periods of intense heat."
If you spot something unusual, have it checked rather than waiting for the next major weather event. A small roofing problem can become much more expensive once rainwater, snow, or ice are involved.
What to Look For in Your Attic
Attics naturally get hot, but without enough airflow, it can trap hot air beneath the roof. This lack of ventilation puts stress on the insulation and the roof structure, and it can also contribute to moisture problems.
If you haven't been in your attic since spring, take a look now. Check for damp insulation, mold, moisture stains, or blocked vents.
One thing that really helped us was the installation of a whole house fan that automatically turned on when temperatures reached a certain point. By forcing circulation and exhaustion, we were better able to manage higher temperatures in the attic.
Should you install a different roofing material?
If your roof is nearing replacement, the experience of this summer may give you good reason to compare your options, including opportunities for solar panels or solar shingles.
"Solar-reflective asphalt shingles, such as CertainTeed's Landmark® Solaris®, reflect more solar energy and absorb less heat than conventional shingles, helping to reduce roof surface temperatures during periods of intense sun exposure," explained Moore, highlighting a product category that’s an accessible alternative for homeowners who want to stick with conventional shingles.
"Additionally, solar shingles, such as CertainTeed's Solstice Shingle, are an innovative solar roofing solution that combines the benefits of traditional asphalt shingles with the power of solar energy. Modern technology allows these shingles to perform similarly to traditional roofing. Rated to be installed in any wind zone, CertainTeed's Solstice Shingle is built to withstand harsh weather conditions, including extreme heat."
Composite roofing is also gaining popularity. "[Brava tiles] reflect a portion of the sun’s energy, reducing heat transfer into the building," shares Brian Davis, Lead Support Director at Brava Roof Tile. "High solar reflectance and thermal emittance contribute to lower roof temperatures, decreased air conditioning demand, and energy savings."
When comparing options, experts unanimously recommend looking at more than heat resistance alone. Homeowners should also consider impact resistance and the shingle's Solar Reflective Index (SRI). SRI measures how well a surface reflects solar energy and releases absorbed heat.
What should you do if summer heat damaged your roof?
You don't need to wait for a leak before having a potential problem checked. A visual inspection from the ground can reveal missing or damaged materials, while an attic check can uncover moisture or ventilation problems.
If you find damage, don't put off getting it checked simply because the hottest weather has passed. Fall and winter weather can put additional strain on an already weakened roof.
Have a certified contractor inspect the roof and identify repairs. For older roofs, that inspection can also help distinguish normal aging from damage that needs repair.
FAQ
Can summer heat cause a roof to leak?
Heat doesn't cause a leak the same way a branch falling on your roof would, but it can worsen cracks, put stress on shingles and underlayment, and exacerbate weak spots that might be on the brink of water penetration. If you've noticed a new leak after a particularly hot summer, it's worth having the roof inspected to find the source.
Is a roof more vulnerable to heat as it gets older?
An aging roof can have more existing wear, which can limit its ability to endure repeated heat exposure. That doesn't mean every older roof needs to be replaced, but you should pay closer attention to changes in its material, condition, installation, ventilation, and other parts of the roofing system.
