San Francisco Bay Area
Roof repair in the Bay Area: the rules and roofs you are working with
Bay Area roofs see long dry summers, winter storms that arrive all at once, coastal fog and salt on one side of the hills and inland heat on the other. California adds its own layer: a state license for roofers, a permit for every reroof, and an energy rule for some of them. Here is what that means for your house.
Who may work on a California roof?
California licenses roofing contractors through the Contractors State License Board, under the C-39 roofing classification. Before you let anyone start, look up their license number on CSLB's Check A License page: it shows whether the license is active, its classification, and whether there is a bond and workers' compensation on file. A general contractor may take on roofing as part of a larger project, but for a roof-only job the C-39 is the license to look for.
The contract itself is regulated too. On a home improvement job the down payment may not exceed $1,000 or 10 percent of the price, whichever is less, and the payment schedule must follow the work actually done. A roofer who asks for half up front to "order materials" is asking for something the law does not allow.
Reroof permits and the cool roof rule
Replacing a roof in California needs a building permit, and the job has to meet the Energy Code (Title 24, Part 6). The Bay Area Regional Energy Network's guide sums up the part people trip over: when half or more of a roof is replaced, cool roof requirements apply in the Bay Area only in Climate Zone 4, which covers parts of Santa Clara County, and Climate Zone 12, which covers parts of Alameda, Contra Costa and Solano Counties. Steep-slope roofs there need roofing with an aged solar reflectance of at least 0.20 and thermal emittance of 0.75 (or SRI 16); low-slope roofs need 0.63 and 0.75 (or SRI 75), plus roof insulation in most cases. Coastal zones are not covered by the reroof cool roof rule. The details and exemptions are on our cool roof page.
The roofs you see around the Bay
| Roof | Where it shows up | What usually needs attention |
|---|---|---|
| Asphalt shingle | Most post-war and newer houses | Flashing, pipe boots, wind-lifted tabs, granule wear on sunny slopes |
| Concrete and clay tile | Many hillside and newer subdivisions | Cracked or slipped tiles, worn underlayment beneath sound-looking tile |
| Flat or low-slope | Mid-century homes, additions, garages, porches | Seams, drains and ponding; insulation and reflectance rules at replacement |
| Wood shake | Older homes, some wooded areas | Splitting, moss on shaded slopes, fire-related rules where they apply |
| Metal | Some newer and rural homes | Fasteners, sealant at laps and trim |
Getting ready for the winter storms
Most Bay Area roof trouble arrives with the first big storms after a dry season, when months of leaves, needles and dust have settled in valleys and gutters and the sun has dried out sealant and rubber boots. A short pre-winter list saves most emergency calls:
- Clear gutters, downspouts and valleys, and make sure downspouts carry water away from the house.
- Look at the roof from the ground with binoculars for missing or lifted shingles, cracked tiles and loose ridge caps.
- Check the attic for old stains, so you know what is new after the first rain.
- Trim branches that touch or hang over the roof.
- On a flat roof, clear the drains and scuppers and look for blisters and open seams.
Flat roofs on Bay Area houses
Flat and low-slope roofs are common on mid-century designs, on room additions and over garages, and they behave differently from pitched roofs: water sits instead of running off. Repairs have to match the membrane already there. A full replacement in most Climate Zones brings two Energy Code requirements at once, reflectance and insulation, which affects both the product and the edge details where the roof gets thicker. Ask about both when you collect bids, and see roof replacement for the rest of the job.
When the roof leaks during a storm
Contain the water inside, turn off power to wet fixtures at the breaker, take photos, and keep off a wet roof. A properly fastened tarp is the bridge to a dry day; our emergency roof repair page explains how it should be done. After the storm, the roof leak repair page walks through tracing the entry point.
Storm damage and insurance in California
Wind and falling limbs cause most storm claims around the Bay. The claim is yours to file with your insurer; a roofer documents what they find and writes the repair scope. Public adjusters are licensed separately in California, so a roofer offering to "handle" your claim is offering something that is not theirs to offer. Our roof insurance claim page lists what to photograph and keep.
Send a Bay Area roof request
Tell us what the roof is doing, what it is made of if you know, and the city or ZIP. We call or email you back about it; the request is free and commits you to nothing.
Bay Area roof questions
Which parts of the Bay Area fall under the reroof cool roof rule?
Climate Zone 4, which covers parts of Santa Clara County, and Climate Zone 12, which covers parts of Alameda, Contra Costa and Solano Counties, when half or more of the roof is replaced. Check your exact address on the California Energy Commission's climate zone tool, because zone lines do not follow city limits.
How do I check a roofer's California license?
Ask for the license number and enter it on CSLB's Check A License page. Look for an active status, the C-39 roofing classification or a general license that fits the job, and current bond and workers' compensation details. A number that does not match the business name is a reason to stop.
What should I check on my roof before the winter rains?
Gutters, downspouts and valleys first, because blocked drainage causes many first-storm leaks. Then look from the ground for missing shingles, cracked tiles and loose ridge caps, trim overhanging branches, and note any old attic stains so new ones stand out after the first rain.
Sources: Contractors State License Board, C-39 Roofing classification, Check A License and Industry Bulletin #22-14; BayREN, Residential Roofing: Guide to 2022 Energy Code Requirements (updated 2022-12-20); California Energy Commission, climate zone tool.