What to do, and when

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.

Look in the attic after heavy weather

Check after the first real weather of the season rather than at the end of it. A small stain found in autumn is a cheap repair; the same stain found in spring is not.

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.

Deal with growth properly

Moss and algae hold water against the surface. Treat and brush gently, or fit zinc or copper strip near the ridge. Never pressure wash an asphalt roof — it strips the granules and takes years off it in an afternoon.

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.

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.

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.