Western Washington might not be famous for sweltering summers, but when the temperatures rise, your roof still feels it. Summer weather quietly creates wear and tear that can shorten your roof’s lifespan, raise your energy bills, and even lead to serious damage in the long run.
Knowing how hot weather affects your roof is a big part of keeping your home or business protected, comfortable, and energy-efficient. Here’s everything you need to know about heat and your home.
How Heat Affects Your Roof
As the summer months roll in, your roof becomes your first line of defense, battling extreme heat, UV rays, and dramatic temperature swings. Here’s how the damage happens.
Expansion and Contraction of Roofing Materials
Roofing materials like asphalt shingles and metal roofs expand when heated and contract when cooled. Over time, this constant movement can cause cracks, loosened fasteners, and warped surfaces. These seemingly small issues can create big vulnerabilities once the rain returns.
UV Radiation and Material Degradation
Even on moderately warm days, UV rays break down roofing material at a chemical level. Asphalt shingles can dry out, become brittle, and lose their granules (the tiny protective particles that shield your roof from heat and water damage).
Moisture Evaporation and Sealant Breakdown
Sealants used around flashing, vents, and other roof penetrations can dry out and crack under prolonged exposure to extreme weather. Once that happens, leaks aren’t far behind.
How Hot Does a Roof Get on a 90-Degree Day?
You might be surprised: when it’s 90°F outside, roof temperatures can easily skyrocket to 150°F or more. The type of roofing material matters a lot:
| Roofing Material | Average Roof Temperature |
| Asphalt Shingles | 140°F – 190°F |
| Metal Roofs | 120°F – 160°F |
| White Roofing (cool roofs) | 100°F – 120°F |
| Tile Roofs | 120°F – 150°F |
How Much Heat Does a Roof Absorb?
The amount of heat absorbed depends on the roofing material, its color, and the angle of the roof. In general, dark, asphalt-based roofing material can absorb 85% to 95% of the sun’s energy, while light-colored or reflective roofing materials often absorb under 50%. This huge difference in heat absorption directly affects roof temperature, cooling costs, and the longevity of roofing systems.
However, as a rule of thumb, Washington’s small amount of summer sunshine isn’t enough to warrant the need for light colored roofs. If you don’t want one, don’t feel pressured to get one. Unless you have very poor ventilation or a low slope/flat roof, a light-colored roof is not something you need to invest in here in the Pacific Northwest.
How Hot is Too Hot for Shingles?
Most asphalt shingles are rated for up to around 140°F surface temperatures. Beyond that, oils in the shingles can dry out, making them brittle and inflexible. The protective granules in asphalt loosen, accelerating wear and tear. If your roof consistently sees temperatures higher than this during the summer months, it may be time to call the repairman and consider some other options.
Tips to Reduce Heat on Your Roof in the Summer
So you know how heat affects your roof, now what do you do about it? Though it may seem hopeless, fear not. There are actually several ways to lower your roof’s heat load, which can not only save your home from extreme heat damage, but also reduce your energy bills. Here’s how:
Cool Roof Coatings and Reflective Paint
These coatings reflect more sunlight and absorb less heat. White roofing systems can keep roof temperatures up to 50°F cooler than standard materials.
Improving Roof Ventilation
Good attic ventilation prevents hot air buildup, extending your roof’s life and making your home more energy-efficient.
Installing Radiant Barriers
Placed under the roof decking, these barriers reflect heat back toward the roof, keeping your attic cooler.
Extra Steps To Preventing Heat Damage
- Schedule annual inspections: catch small problems before they get worse.
- Upgrade to cool roofing materials: especially important if you’re replacing your roof.
- Improve insulation and ventilation: keep your roof and attic temperatures lower.
- Clear debris: keep gutters clean and clear to prevent water buildup and added heat absorption.
How to Get Hot Air Out of Your Roof Space
The amount of heat absorbed depends on the roofing material, its color, and the angle of the roof. In general, dark, asphalt-based roofing material can absorb 85% to 95% of the sun’s energy, while light-colored or reflective roofing materials absorb far less, often under 50%. This huge difference in heat absorption directly affects roof temperature, cooling costs, and the longevity of roofing systems.
Does Painting a Roof Reduce Heat?
Yes, but it’s not a silver bullet. Reflective roof paints can lower roof temperature temporarily, but for lasting results, pairing cool paint with improved ventilation and insulation is a smarter long-term investment.
Final Thoughts
Heat-related roof damage might not be obvious right away, but ignoring the signs can lead to expensive repairs or even early roof replacement. It’s smart to take proactive measures to help your roof along those hot summer months, even in Western Washington.
Why Choose The Roof Doctor for Your Roof Protection and Repair Needs?
At The Roof Doctor, we’ve spent over 60 years providing comprehensive care for the lifetime of your roof. As a family-owned, local business, we understand the unique weather conditions of Western Washington, from extreme heat to torrential rains. Our highly trained crews are here for you 24/7, delivering fast, reliable service with a friendly, welcoming attitude. Whether you need an inspection, repair, or full replacement, you can count on us to get the job done right.
Licensed, bonded, and insured, we’re proud to bring home-grown values and unmatched expertise to every project.
