Signs You Need a New Roof: What Dayton Homeowners Should Look For

How do you know when you need a new roof?

Owens Corning, the company that makes the shingles we install, lists seven signs (opens in a new tab) that a roof may need replacing:

• Shingle edges that curl, or shingle tabs that cup.
• Bald spots where the granules are missing.
• Cracked shingles.
• A roof that is at least 20 years old, or looks old and worn.
• Neighbors getting new roofs.
• Dark streaks.
• Moss.

Two more mean you should call a roofer right away: water stains on a ceiling, and a roof deck that sags.

How old is too old for a roof?

Around 20 years is when most roofs start showing their age. A properly installed roof lasts 20 to 40 years, and how well it was installed and ventilated matters as much as how old it is. Here's a simple check: if the houses on your street were built around the same time as yours and your neighbors are getting new roofs, yours is probably close too. Same age, same weather.

What do curling or cupped shingles mean?

Curled edges and cupped tabs mean the shingles are wearing out, and poor attic ventilation speeds that up. Owens Corning says a roof that isn't properly ventilated "can negatively impact your shingles," and its warranty doesn't cover damage from poor ventilation (opens in a new tab). If your shingles are curling, the attic airflow is worth a look before the new roof goes on.

What do granules in the gutters mean?

Bald spots where the granules have worn off mean the shingles are wearing out. If you find piles of granules in your gutters, or bare patches on the roof, have it checked.

Is a sagging roof a sign you need a new one?

Yes, and don't wait on it. A dip in the roofline can mean a problem in the roof deck or the framing under it. When we replace a roof, we tear it off down to the deck, and any rotted wood is cut out and replaced before anything new goes on.

Are dark streaks or moss a reason to replace a roof?

Not by themselves. Dark streaks are algae. Owens Corning says they may not hurt the shingles, but they "won't look good." Moss is a different story, because it "can hold moisture against the roof surface." On an older roof, either one is a good reason to have the whole roof looked at.

Read more: what causes black streaks on a roof

Should I repair my roof or replace it?

We don't patch roofs. When we do a roof repair, we rebuild the whole elevation that's leaking, and the repair carries our Lifetime Workmanship Warranty. On a roof that's 20 years or older, especially one with two layers, a repair usually isn't worth it. It's hard to find a shingle that matches, and the rest of the roof is just as old. That's when we recommend a new roof.

Can a new roof go over the old one?

Not if it already has two layers. The Residential Code of Ohio doesn't allow a new roof over two or more layers (section 908.3.1.1 (opens in a new tab)). We don't put a new roof over an old one at all, even when code would allow it. Every roof we replace is torn off to the deck, so we can see the wood underneath and fix it.

What can I check myself, and what should a roofer check?

Stay off the roof. From the ground, look for curled or missing shingles, bare spots and a wavy roofline. Check your gutters for granules and your upstairs ceilings for stains. Then have a roofer take a look. On our free roof inspection, we check the entire property from the ground, then the whole roof, and we photograph and explain everything we find. We tell homeowners to have their roof looked at every five years, and any time something looks wrong.

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Next step

Next step: see what goes into a new roof, layer by layer.

See our Dayton roof replacement prices and the online roof calculator, or book a free roof inspection.