How long does each roofing material last?
| Roofing material | Estimated life (years) |
|---|---|
| Asphalt shingles (3-tab) | 20 |
| Asphalt shingles (architectural) | 30 |
| Wood shakes or shingles | 25 |
| Metal | 40 to 80 |
| Clay or concrete tile | 100+ |
| Slate | 60 to 150 |
| Built-up roofing (flat) | 30 |
| Modified bitumen (flat) | 20 |
| TPO (flat) | 7 to 20 |
| EPDM rubber (flat) | 15 to 25 |
Source: InterNACHI Standard Estimated Life Expectancy Chart. InterNACHI notes that these are guidelines for normal wear with recommended maintenance, not guarantees.
How does the weather in the South Bay affect roof life?
The Santa Clara Valley has warm, dry summers and long sunny stretches, which age asphalt shingles faster; InterNACHI notes that hot climates drastically reduce asphalt shingle life. Foothill homes in Los Gatos, Saratoga and the east hills add tree debris and wildfire exposure.
How can I find out how old my roof is?
- Permit history. Most building departments can look up past permits for your address, including reroofs.
- Purchase paperwork. Your home inspection report and the seller's disclosures often note the roof's age or last replacement.
- Invoices and warranties. A roofing contract or manufacturer warranty registration shows the install date.
- A roofer's assessment. A licensed roofer can estimate remaining life from the materials and their condition, with photos.
How old are homes in the South Bay?
Palo Alto's median home dates to 1963, Cupertino's to 1973, and San Jose's and Sunnyvale's to 1976. Those decades produced large tracts of similar homes, including many Eichlers with flat or low-slope roofs, so whole neighborhoods tend to reach replacement age around the same time.
What does roof age mean for my insurance?
Insurers use roof age in underwriting. Beginning January 1, 2028, SB 1301 bars an insurer from refusing or nonrenewing a policy solely because of roof age when the policyholder pays for an independent inspection showing at least five years of useful life left. See our insurance guide.
Frequently asked questions
How long does a shingle roof last?
InterNACHI estimates about 20 years for 3-tab asphalt shingles and about 30 years for architectural shingles under normal conditions with maintenance.
How long does a metal roof last?
InterNACHI's chart estimates 40 to 80 years for metal roofing.
How long does a flat roof last?
It depends on the system. InterNACHI estimates about 30 years for built-up roofing, 20 for modified bitumen, 7 to 20 for TPO and 15 to 25 for EPDM rubber.
How do I find my roof's age?
Check your city's permit history for your address, your purchase inspection report and disclosures, and any roofing invoices or warranty paperwork, or ask a licensed roofer to assess it.
Sources
Sources reviewed November 11, 2026. Figures are published estimates and official fees, not quotes. Confirm prices, permits and requirements with your contractor and building department. This page is general information, not legal or insurance advice.