My roof is 20 years old. Should I replace it?

Twenty years is the point where most asphalt shingle roofs in the Bay Area move from “keep an eye on it” to “start planning”. It does not mean the roof has to come off this year. It means the next decision should be based on an inspection, not on a leak in the middle of a storm.

What does 20 years mean for my type of roof?

The Bay Area figures are the ones we see in the field (see how long a roof lasts in San Francisco); the 3-tab figure is from InterNACHI’s life-expectancy chart.

What are the signs a 20-year-old roof needs replacing?

• Leaks in more than one place, or leaks that move around the house.
• Granule loss across the roof, with bare spots and granules piling up in gutters.
• Curling, cracking or brittle shingles that break when lifted.
• Soft or spongy spots underfoot, or a sagging roofline.
• Blisters, splits and ponding across a flat roof, not just in one spot.
• Paying for repairs every rainy season.

When does a repair still make sense?

If the damage is in one place, such as one flashing detail, a few blown-off shingles or a cracked pipe boot, and the rest of the roof is sound, a repair can buy useful years. Our San Francisco roofing guide uses a simple test: repair when damage is localized and the repair costs less than about 30% of a replacement; replace when the roof is 20 or more years old and wear shows in several areas. For the longer version, see roof repair vs. replacement.

Why plan the replacement instead of waiting?

• Timing. You can book a dry-season install and avoid a storm-day emergency.
• Bids. You have time to compare written estimates for the same scope.
• Insurance and sale. Insurers typically cover sudden damage, not wear and age, and buyers’ inspectors will flag an aging roof. The California Department of Insurance has consumer guidance on what policies cover.
• No shortcuts. California code does not allow a new layer over a roof that already has two or more layers, so many older roofs need a full tear-off anyway.

A free roof inspection gives you photos and an honest estimate of the years left, and, when it is time, an itemized quote for roof replacement. If you are in the city, our roofing in San Francisco page covers local permits and building types.