How Long Does a Roof Last?

Roof lifespan by material

These are the published figures, each from the body that published it. They are typical service lives, not guarantees for a particular roof:

The Asphalt Roofing Manufacturers Association adds a practical rule of thumb for shingles: a roof more than 20 years old is a prime candidate for reroofing. For metal, the Metal Roofing Alliance notes that a worn finish "can often be repainted versus replaced".

How long does a roof last in California?

The figures above apply in California too; the sources above give no separate California figures. What can end a California roof early is the fire code rather than wear.

CAL FIRE calls the roof "the most vulnerable part of your home". In State Responsibility Areas and in local High and Very High fire hazard severity zones, a re-roof of 50 percent or more within 12 months must be a Class A assembly, so a covering that is not Class A comes off at the next re-roof whatever its age. Our guide to Class A fire-rated roofing explains the rule.

Underlayment under tile: why the tiles outlive it

A tile roof often looks fine long after it has started to fail, because the tiles are only part of the system. The Tile Roofing Industry Alliance calls the underlayment "critical to the success of the roof system" and, in most cases, the secondary water barrier that carries away the water that gets past the tiles. No lifespan in years is published for tile underlayment, so its condition is checked by lifting tiles rather than guessed from the age of the roof.

When the underlayment has failed but the tiles are sound, the fix is a lift and relay: the tiles come off, the underlayment and flashing are renewed, and the sound tiles go back on. See tile roof underlayment replacement.

Roof Replacement

Signs your roof is near the end

• Leaks in more than one area, or new leaks soon after earlier repairs
• Shingles that are curling, cracking or losing their granules across whole slopes
• Soft, spongy or sagging areas that point to a damaged deck underneath
• Many cracked or slipped tiles, or brittle underlayment under the tiles
• Water staining in the attic along several rafters, or daylight through the deck

One of these on its own is often a repair. Several together, on a roof near the ages in the table, usually point to a replacement.

Repair, re-roof or wait: how to decide

Three questions settle most decisions. Is the damage local or spread across the roof? Is the roof near the end of its typical life for its material? And is anything about to go on top of it, such as solar panels, that would be expensive to take off later?

On that last point, the California Public Utilities Commission advises replacing a roof that is due soon before installing solar. The Department of Energy puts the life of solar panels at about 25 to 30 years, so the roof under them should have at least that much life left. See whether to replace your roof before solar.

A roof inspection with photos answers the first two questions for your roof, and ends with an estimate of the remaining life, labelled as an estimate.

Other questions