Signs your roof is finished

Granules in the gutter

The granules are the sunscreen. Losing them in volume means the asphalt beneath is being cooked directly, and from that point the roof ages in years rather than decades.

Shingles that curl, cup or go brittle

A roof near the end goes hard. Shingles that were pliable enough to seal down in the sun no longer bond, and the first serious wind takes them.

Sagging along a line

A ridge or a plane that dips is a structural signal rather than a covering one. It usually means decking that has been wet long enough to lose strength, and occasionally framing. This is the one symptom that should not wait.

Repeated repairs in different places

When the leaks stop clustering and start appearing anywhere, you are not fixing a fault any more. You are paying for a replacement in instalments, at a worse rate.

The age on the paperwork

If the roof is over twenty years old and made of asphalt, an inspection is worth doing whether or not it is leaking. The failure modes above are much cheaper to catch before the water arrives than after.

Daylight or damp in the attic

The attic tells the truth earlier than the ceiling does. Staining on the underside of the deck predates any stain you will see downstairs by a long way.

In short

If two or more of these apply, get somebody to look at it and give you a remaining-life number in years. That single number turns the decision from a worry into arithmetic.