What to do, and when

Cut back anything touching the roof

Overhanging limbs cause three problems at once: abrasion, permanent shade that keeps a slope damp, and a highway for rodents into the attic.

Clear the gutters before the wet season

Gutters full of grit are not just a drainage problem — the grit is your roof, and its presence tells you something about how far along the covering is.

Twice a year, from the ground

You do not need to be on the roof to find most problems. A slow lap of the house at a low angle finds nearly all of them.

Deal with growth properly

Cleaning a roof aggressively does more damage than the growth was doing. Gentle treatment, patience, and a strip at the ridge to stop it returning.

Look in the attic after heavy weather

The attic shows a leak long before the ceiling does. After any serious storm, take a torch up and look at the underside of the deck around penetrations and valleys.

Keep the penetrations honest

Pipe boots crack, sealant shrinks, and satellite mounts get screwed straight through the covering. Every penetration is a hole somebody decided to make watertight, and each is worth a look.

In short

None of this is difficult and none of it is expensive. It is simply the difference between a roof that reaches its rated life and one that does not.