What to do, and when

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.

Clear the gutters before the wet season

Blocked gutters back water up under the bottom course of shingles and rot the fascia behind them. This is the highest-value hour of maintenance there is, and here it wants doing before November through March.

Twice a year, from the ground

Walk the perimeter with binoculars if you have them. You are looking for missing or lifted material, dark patches, sagging lines, and anything growing where it should not be. Ten minutes, twice a year.

Keep the penetrations honest

Rubber pipe boots are the single most common source of leaks on an otherwise sound roof, and they are cheap to replace before they fail.

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.

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.

In short

Put two dates in the calendar, one either side of November through March. That is the whole programme.