How to tell a roof is past repairing

Sagging along a line

Straight lines going wavy means something underneath has softened. That is no longer a roofing question with a cheap answer.

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.

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.

Shingles that curl, cup or go brittle

Look along the roof from the ground at a low angle rather than straight on. Edges that lift, corners that curl upward and a surface that no longer lies flat all mean the material has lost its flexibility. Brittle shingles crack when walked on, which is why contractors stop wanting to walk them.

Granules in the gutter

Asphalt shingles are protected by a granular surface. When that surface starts washing off in quantity, the mat underneath is exposed to ultraviolet and the clock speeds up sharply. A handful of granules after a new roof is normal shedding. Cupfuls, years later, is not.

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

None of these on their own settles it. Two together usually do. An inspection costs little and removes the guesswork entirely.