Today when we talk about wildfire prevention, we focus on defensible space and home hardening, and we rarely mention wood shake roofs. Starting in Jan-2022, the Town Council banned new wood roofs, but at least 84 homes in Portola Valley have existing wood roofs.

So, let’s recap some research. In the 1961 Bel Air Fire in Los Angeles, 50% of homes with wood roofs within 30 feet of burning vegetation ignited, versus 24% with fire-resistant roofs. In the 1991 Oakland Hills Fire, every burning home contributed to the ignition of 10 other homes. In 1994 research, 70% of nonflammable roofs survived versus 19% of flammable roofs. In the 2023 Lahaina Fire, 80% of non-Class A roofs ignited.

Scientists know that wood roofs are such a large factor in ignitions, that they mask all other vulnerabilities. IBHS considers each wood roof an entry point for fire into a neighborhood, and it has declared that no community with a wood roof can qualify for their upcoming Wildfire Prepared Neighborhood designation.

A new roof is a considerable expense, but you cannot ignore the wildfire risk inherent in your wood roof. Embers will not. Insurers will not.

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