Walk around your house and look up at the roof. You don’t need to climb anything — a pair of binoculars or a zoomed phone photo from the ground works fine. What you’re looking for is shingle damage, and it comes in three main flavors: curling, cracking, and missing. They sound similar. They are not. Each one points to a different problem, and each one asks for a different response.
Here’s how to read what your shingles are telling you.
Curling Shingles: The Roof Is Aging Out
Curling is when shingle edges lift or turn — either the corners lift (cupping) or the edges curl downward toward the roof (clawing). It’s the most common visible sign of an aging asphalt shingle roof, and it almost always means heat and time, not impact.
Asphalt shingles are basically a fiberglass mat soaked in asphalt and coated with granules. Years of sun and heat cycling cook the asphalt out. The mat shrinks unevenly, and the edges pull up or push down. Poor attic ventilation speeds this up dramatically — heat trapped under the deck cooks the shingles from below while the sun cooks them from above. A roof with a hot, unvented attic can curl a decade before the same shingles on a ventilated roof would.
What to do about it depends on how far it’s gone. A few slightly cupped shingles on one hot south-facing slope are worth watching. Widespread curling across the whole roof is the classic sign that replacement is on the horizon — curled shingles no longer seal properly against each other, so they’re vulnerable to wind uplift, and the raised edges shed granules faster. Once curling is everywhere, patching is just postponing.
There’s a middle case worth knowing about: localized curling on one slope can mean a ventilation problem rather than a roof-age problem. If the south slope is curling and the north slope looks fine, the attic airflow deserves a look before you assume the whole roof is done.
Cracked Shingles: Stress, Impact, or Bad Installation
Cracks are splits in the shingle, usually running vertically from the bottom edge up. They’re different from curling because they usually mean something happened to the shingle — not just that it got old.
The most common cause is thermal stress. Shingles expand and contract with temperature swings, and after years of cycling, the asphalt becomes brittle enough that the movement cracks it. This shows up most on roofs in climates with big daily or seasonal temperature swings, and it accelerates once granule loss has exposed the asphalt to direct sun.
Hail is the other big cause. Hail doesn’t just knock granules off — hard enough hits crack the mat underneath. These cracks can be hard to see from the ground because the shingle may look intact at a glance, but a close look (or a roofer’s inspection) reveals fractured spots where the crack lets water straight through to the underlayment.
Installation problems cause a third kind of cracking. Shingles nailed too high, too hard, or in cold weather can crack at the nail line. These cracks show up early — within the first few years — and they’re a workmanship problem, not a materials problem.
The response depends on the cause and the count. A handful of thermally cracked shingles can be individually replaced — a competent roof repair job, not a replacement. But cracks that are everywhere, especially from hail across the whole roof, usually mean the shingles have lost their weatherproofing as a system. And installation-caused cracking across a young roof may be a warranty conversation with the original installer.
Missing Shingles: Wind Wins
Missing shingles are the most urgent of the three. A curled shingle still sheds most water; a missing shingle leaves the underlayment — or bare deck — exposed. Every storm that hits that spot pushes water directly at the layer that was only ever meant to be backup.
Wind is almost always the cause. Shingles have adhesive seal strips that bond them together after installation, plus nails. When the seal strips fail to bond — because the roof was installed in cold weather, because the shingles are old and the seal has let go, or because the adhesive has cooked out with age — wind gets under the tab and peels it off. This is why missing shingles so often follow a storm: the wind was just the test the seal had been quietly failing for years.
How many matters enormously. One or two missing shingles after a storm is a straightforward repair — a roofer can slip replacements under the course above and seal them down. But if a storm took dozens of shingles across multiple slopes, or if shingles are disappearing in normal wind, the seal system has failed broadly and the roof is telling you it’s near the end. Repairing twenty scattered spots on a failing roof costs real money without buying much more life.
Also: never leave missing shingles “for later.” Underlayment buys you some time — days to weeks, not months. If you can’t get a roofer quickly, an emergency tarp over the bare spot beats hoping for dry weather. A small leak found early is a repair; the same leak found after two months of rain is drywall, insulation, and possibly mold.
Reading the Combination
Real roofs rarely show just one type of damage. Here’s how to read the combinations:
- Curling + granule loss in gutters — the roof is simply old. Start planning for replacement rather than stacking repairs.
- Cracking concentrated after a hailstorm — likely storm damage; document it and read up on how the claims process works before calling anyone.
- Missing shingles on an otherwise young roof — suspect installation or seal-strip bonding problems; a roofer can diagnose this from the attic side too.
- All three across the whole roof — the roof is done. Repairs will keep costing money without extending life meaningfully. Time to think about a full replacement.
The through-line: curling tells you about age, cracking tells you about stress or events, and missing shingles tell you about urgency. Learn which one you’re looking at and the right next step gets much clearer.
For a broader picture of your roof’s condition beyond the shingles, the warning-signs guide walks through the other early indicators of trouble — leaks included — so you can catch problems while they’re still small.