People tend to think of winter as the hard season for roofs in Michigan. And it is tough,but summer has its own way of wearing a roof down, and it does it quietly, over years, without the dramatic evidence of an ice dam or a missing shingle after a windstorm.
If your roof is approaching the 15-year mark, understanding what summer heat is doing to it can help you make smarter decisions about maintenance, repairs, and when replacement makes sense.
UV Degradation: The Slow Burn
Asphalt shingles are designed to hold up to sun exposure, but they are not immune to it. The granules embedded in the surface of each shingle serve as UV protection; they absorb and deflect solar radiation before it can break down the asphalt layer beneath. Over years of Michigan summers, those granules slowly erode.
Once granule coverage thins out, UV rays begin degrading the asphalt directly. Shingles become brittle, lose flexibility, and start to crack. On a hot August day in Lansing, a roof surface can reach 150 to 160 degrees Fahrenheit. That thermal stress, repeated day after day across a Michigan summer, accelerates aging significantly.
If you are finding granules in your gutters or at your downspout splash pads after summer rains, that is your shingles telling you they are working harder than they used to.
Thermal Expansion and Contraction
Every time your roof heats up during the day and cools at night, the materials expand and contract slightly. Over time, this movement stresses the fasteners holding shingles in place, works at the seals between shingles, and can gradually loosen flashing around chimneys, vents, and skylights.
This is why flashing inspections matter even when you have not had a storm. A flashing seal that was tight last October may have shifted over the summer and become a potential entry point for water before the fall rain season begins.
Attic Heat Buildup and What It Costs You
A poorly ventilated attic in summer can reach temperatures of 140 to 150 degrees or higher. That heat does two things: it drives up your cooling costs because it radiates down into your living space, and it cooks your roof deck and shingles from below, accelerating the aging process on both sides.
Proper attic ventilation, a balanced combination of intake at the soffits and exhaust at the ridge, keeps air moving and prevents that heat from building up. If your attic is excessively hot in summer, adding ventilation is one of the more cost-effective improvements you can make for both energy efficiency and roof longevity.
Capital Roofing evaluates ventilation as part of our standard roof inspections, and we replaced shingles and added venting on a recent job in Lansing where the homeowner had been dealing with premature shingle wear caused largely by inadequate attic airflow.
Summer Storms: The Other Summer Threat
Michigan summers also bring severe thunderstorms, high straight-line winds, and occasional hail — sometimes all in the same afternoon. A healthy roof handles these without much issue. A roof that has already been compromised by years of UV exposure and thermal stress is more vulnerable.
After any significant summer storm, it is worth doing a quick ground-level inspection. Look for missing or displaced shingles, check your gutters for granule accumulation, and look at soft metal surfaces like flashing and AC units for hail impact dents. If you see evidence of impact on metal surfaces, have the roof looked at professionally.
The Case for a Mid-Summer Inspection
Most homeowners think of roof inspections as a fall or spring thing — and those are great times. But if your roof is older or you have had some rough summer weather-wise, a mid-season inspection gives you a clear picture of where things stand before the fall storm season arrives.
It also gives you time to address anything that comes up without the urgency of winter approaching. Summer repairs can be scheduled at your convenience, materials are readily available, and you are not racing against a forecast.
Ready to schedule your free roof inspection? Call or text Capital Roofing at (517) 896-5872 or visit capitalroofingpro.com. Serving Lansing, East Lansing, Grand Ledge, St. Johns, Okemos, and communities across Greater Lansing.