What you can see from the ground
Binoculars and a sunny afternoon are enough for most of this. Look at the south and west slopes first; they wear out fastest.
- Shingle edges curling up, or the middles cupping down.
- Patches where the shingles look smooth and dark because the granules are gone.
- Cracked or missing shingles in more than one area.
- A wavy or sagging roofline, which can mean the deck underneath is failing.
- Rusted, lifted or caulk-covered flashing around the chimney and where the roof meets a wall.
What turns up in the gutters
Asphalt shingles shed some granules when new. On an older roof, gutters and the bottom of downspouts full of gritty granules mean the shingles are losing their protective layer.
What the attic tells you
On a dry day, go up with a flashlight. Turn the light off for a moment once your eyes adjust.
- Daylight showing through the roof boards.
- Dark stains or soft spots on the roof deck or rafters.
- Frost or wet insulation in winter, which points to ventilation trouble as well.
- Nail tips that are rusty or dripping on cold mornings.
See also: Attic ventilation and condensation
Inside the house
- Ceiling stains that grow after storms or during a thaw.
- Peeling paint or bubbling plaster near the top of exterior walls, a common ice dam sign.
- A musty smell in top-floor closets or a finished attic.
Replace or wait
Age matters as much as any single sign. A 10-year-old roof with storm damage on one slope is a different conversation from a 25-year-old roof with curling across every slope. When several signs line up on an older roof, piecemeal fixes tend to follow each other, and a replacement before winter is often the calmer path.
After a hailstorm
Hail bruising is easy to miss from the ground. See replacing a roof after hail damage before deciding anything.
Questions
+Is a single leak a sign I need a whole new roof?
Not by itself. Leaks often come from flashing, a vent boot or one damaged area. The age and overall condition of the roof decide whether replacement makes sense.
+Do dark streaks on the roof mean it is failing?
Usually not. Black streaks are typically algae, which is mostly cosmetic. Thick moss is more of a concern because it holds water.
+Should I go up on the roof to check?
It is safer to look from the ground with binoculars and from the attic. Walking an old roof can damage brittle shingles and is a fall risk.