Asphalt shingles

Asphalt shingles cover most Colorado homes because they're affordable, easy to repair and familiar to every roofer. They're also the material most affected by hail. Knowing which type you have and how it was rated helps you read an estimate or an insurance scope.

3-tab vs architectural

3-tab shingles are a single flat layer with two slots cut into each strip, making three "tabs." They look uniform, like a brick pattern. InterNACHI's guideline life for them is about 20 years.

Architectural shingles, also called dimensional or laminated, are two layers bonded together with irregular cutouts. They're thicker, look more textured and are heavier. InterNACHI's guideline is about 30 years. Most roofs installed in Colorado today are architectural.

Both types come in impact-resistant versions. Those are covered on the Class 4 page.

What a shingle is made of

A modern asphalt shingle has a fiberglass mat in the middle, soaked and coated in asphalt. The asphalt is what keeps water out. On top is a layer of ceramic-coated mineral granules.

Granules

Granules give the shingle its color, but their real job is shielding the asphalt from UV light. Once granules are gone, sun breaks the asphalt down faster, and the shingle dries, cracks and curls. Hail knocks granules loose in patches, which is why bare spots after a storm matter even when nothing is leaking.

Sealing strip

Each shingle has a strip of adhesive that bonds it to the shingle below once the sun warms it. That bond is what keeps wind from lifting the edges. Shingles installed in cold weather may not seal until the next warm spell, and they're vulnerable to wind until then.

Wind ratings

Shingle wrappers list wind ratings from two different tests. They're not interchangeable.

Building codes require self-sealing shingles to be classified under D7158. These are test speeds, not guarantees for a real storm. The National Weather Service in Boulder reports foothill winds of 60 to near 100 mph, and some downslope winds exceed 100 mph, mostly in the cold season. If you live near the foothills, a higher rating and careful nailing are worth asking about.

What ages asphalt in Colorado

• Hail. Hail bruises the mat, cracks shingles and strips granules. It's the main reason Front Range roofs get replaced early.
• Sun. UV exposure rises with altitude, roughly 10% per 1,000 meters (about 3,300 feet) according to the WHO. More UV means faster wear on exposed asphalt, though we found no study measuring exactly how much faster shingles age here.
• Wind. Strong winter winds can break the seal strip, crease shingles and tear them off, especially on poorly nailed roofs.
• Temperature swings. Warm days and freezing nights expand and contract the roof repeatedly. As a general rule, this stresses older, brittle shingles and sealants.
• Poor ventilation. A hot attic cooks shingles from below. See how your roof works.

You can check how much hail your area has seen with the free Roof Report. More on local weather is on our Colorado climate page.

Warranties, generally

Shingle warranties usually have two parts. The manufacturer's warranty covers defects in the material, and it often shrinks over time after an initial full-coverage period. The contractor's workmanship warranty covers installation errors. Manufacturer warranties often require the roof to be installed to their instructions, sometimes by a certified installer, to keep full coverage.

Read the hail language carefully. Many shingle warranties exclude hail or limit it, even on impact-rated products. Hail damage is usually an insurance matter, not a warranty claim.

Common questions

How long do asphalt shingles last in Colorado?

InterNACHI's national guideline is about 20 years for 3-tab and about 30 for architectural. In Colorado, hail often ends a roof's life sooner, so treat those numbers as a ceiling, not a promise.

Is it normal to find granules in my gutters?

Some granule shedding is normal on a new roof and as a roof ages. A sudden heavy load after a storm, or bare black spots on the shingles, is worth a closer look. See spotting roof damage.

What wind rating should I look for?

Codes require self-sealing shingles to be classified under ASTM D7158. Class H is the highest, rated to 190 mph in the test. Many architectural shingles also carry ASTM D3161 Class F. Your local code sets the minimum.

Can I put new shingles over my old ones?

Sometimes, but many Colorado jurisdictions limit it. Denver requires tear-off when two or more layers exist, Lakewood always requires tear-off, and Fort Collins allows only one overlay under weight limits.