Does Heat Affect Shingles? Summer Roof Risks in Peoria

Is Summer the Silent Killer of Your Roof?

When we think of roof damage in Central Illinois, we usually picture hail storms or heavy snow loads. But ask any veteran roofer, and they will tell you: Summer heat causes just as much damage as winter ice.

The question isn’t “Does heat affect shingles?”—it’s “How much life is the sun sucking out of my roof right now?” In the height of a Peoria July, your dark asphalt roof can reach temperatures of 160°F. This extreme heat cooks the asphalt, leading to premature aging.

Here is exactly how heat damages your roof and the warning signs you need to look for.

1. The “Thermal Shock” Factor

This is the biggest enemy in the Midwest.

• The Science: During the day, your shingles expand in the 90° heat. At night, the temperature often drops 20-30 degrees, causing them to contract rapidly.

• The Result: Over years of this constant stretching and shrinking, the asphalt becomes brittle. Eventually, hairline cracks form, and the shingles lose their ability to shed water.

2. Blistering (The “Popcorn” Effect)

Have you ever seen small bubbles on your shingles that look like popped blisters?

• The Cause: This happens when moisture is trapped inside the shingle during manufacturing or from high attic humidity. As the sun heats the shingle, that trapped moisture boils and expands, popping a hole in the surface.

• The Risk: once a blister pops, the protective granules fall off, leaving the asphalt exposed to UV rays.

3. “Cooking” From the Inside Out

If your attic is not properly ventilated, heat isn’t just hitting your roof from above—it’s baking it from below.

• The Problem: Hot air rises. If it cannot escape through ridge vents or box vents, it gets trapped in your attic. This superheated air cooks the underside of your shingles (the adhesive layer).

• The Fix: Proper attic ventilation is critical. According to ENERGY STAR, a well-ventilated attic reduces cooling costs and extends roof life.

Signs Your Roof Has Heat Damage

You don’t need to climb a ladder to check for this. Grab a pair of binoculars and look for:

1. Curling Edges: Are the corners of your shingles turning up? This is a sign the asphalt has dried out.

2. Bald Spots: Look for patches where the granules (the sand-like coating) have worn away.

3. Fading Color: If your roof used to be charcoal black and is now a dull gray, UV radiation has compromised the protective coating.

Can You Protect Your Roof from the Sun?

You can’t change the weather, but you can change how your roof handles it.

• Check Ventilation: Ensure your soffit vents (in the eaves) aren’t blocked by insulation.

• Upgrade Materials: If it is time for a replacement, consider architectural shingles or metal roofing, which reflect more UV rays than standard 3-tab shingles.

Don’t let the sun burn a hole in your wallet. If you suspect your roof is suffering from heat exhaustion, contact SNS Roofing today for a free summer inspection.