When deciding if it is time to replace your roof there are several factors that will affect the life expectancy of your roof in the San Francisco Bay Area.

Factors to Consider for Estimating Roof Life Span

1. The style of your roof?.  Flat vs Sloped
2. Type and amount of attic insulation and if there is attic ventilation?
3. How was the prior roof installed?
4. What roofing materials were used when installed?
5. How much shade is casted on the roof?
6. Has there been any debris left on the roof for long periods of time?
7. The microclimate you live in?

General life expectancies of roofing materials:

• Asphalt Shingles (3 tab Shingles):                 15 to 20 years
• Asphalt Architectural Shingles:                        20 to 30 years
• Built-Up Roof: (tar and gravel)                       10 to 20 years
• Modified Bitumen Roof:                                 15-20 years
• Clay and Cement Tile Roof:                            20+ years
• Slate Roof:                                                       30-75 years