Roofs fail slowly and then all at once. The slow part is visible for years if you know what to look at, and almost all of it can be assessed without leaving the ground, which is the safest place to assess a roof from.
1. Granules collecting in the gutters
Asphalt shingles are covered in mineral granules that protect the material underneath from sunlight. As shingles age, those granules let go. They wash into the gutters and collect at downspouts, looking like coarse dark sand.
A handful after a new roof is normal, since loose granules from manufacturing wash off in the first rains. A steady accumulation years later means the shingles are losing their protective layer, and once that is gone the material degrades quickly.
2. Shingles that curl, cup or lift
From the ground, look along the roof plane at a shallow angle rather than straight at it. Curling edges and raised corners show up in that view and disappear when you look head on.
Curling usually means heat, and heat usually means the attic below is not ventilating properly. That is worth knowing, because replacing the roof without fixing the ventilation buys you a shorter second roof.
3. Any sag at all
Look along the ridge line. It should be straight. Any dip, wave or bow in the roof plane is a structural signal rather than a covering one, and it needs someone qualified to look at it soon.
This is the one item on the list that is urgent regardless of the age of the shingles.
4. Flashing, not shingles
Most leaks do not happen in the middle of a roof plane. They happen where the roof meets something else: a chimney, a wall, a vent pipe, a valley between two slopes. Those junctions are handled by flashing, and flashing fails before shingles do.
From the ground you can see rust, gaps, or obvious patch jobs with sealant. Sealant smeared around a chimney is a repair with an expiry date, not a solution.
5. Stains on the ceiling inside
Obvious, but worth stating precisely: a stain means water has already been getting in for a while. Water travels along framing before it appears, so the stain is rarely directly under the entry point.
Asphalt shingles are commonly quoted with a lifespan in decades, but a roof on a poorly ventilated attic, or one installed over an existing layer, can reach the end of it years early. Judge the condition, then check the age.
Getting quotes before you need them
A roof replaced because you decided to is a scheduled purchase with three competing quotes. A roof replaced because water is coming through a ceiling is an emergency purchase with whoever can come tomorrow.
The difference in cost is substantial, and the difference in quality of work is larger, because good roofers are busy and emergency work goes to whoever is not.
Questions people ask
Can a new roof go over the old one?
Sometimes it is permitted, and it is cheaper up front. It also traps heat, hides deck damage and shortens the life of the new layer. Most people who do it regret it at the next replacement.
How often should a roof be inspected?
A ground-level look twice a year and after any major storm is enough for most houses. Get a professional up there when something in that look concerns you.
Does moss actually damage a roof?
It holds moisture against the surface and can lift shingle edges as it grows. It is worth removing gently. Pressure washing removes moss and granules together, which does more harm than the moss did.
Is roof damage covered by insurance?
Sudden damage from a storm is usually covered. Deterioration from age is not, and insurers distinguish between the two carefully. Photograph the roof's condition periodically so you can show what changed.
