The short version
In short: Class A is the highest fire rating for a roof covering, and the rating applies to the tested assembly, including the underlayment listed with it. In Calabasas, roof assemblies must be Class A and wood shake roofs aren’t allowed; the table below shows the rules in nearby cities. Ember-resistant vents, enclosed eaves, and clean gutters matter as much as the roof itself.
Class A is the top rating
Roof coverings are fire-tested and rated Class A, B, or C. Class A resists severe fire exposure.
The assembly is rated
Many products are Class A only with the specific underlayment listed for them.
No wood shakes
Calabasas, Agoura Hills, and Malibu don’t allow wood shake roofs.
Embers find the gaps
Vents, open eaves, and leaf-filled gutters matter as much as the roof covering.
What “Class A” means
Roof coverings are tested under ASTM E108 (also published as UL 790) for how they resist flame spread and burning embers landing on the roof. Class A is the highest of the three ratings.
The rating belongs to the whole roof assembly, not just the visible material. Many tile, metal, and low-slope products are Class A only when installed over the underlayment or cap sheet named in their listing. Installing the right product the wrong way can leave a roof that doesn’t meet code, so we specify and document the complete listed assembly for every permit.
Where Class A is required
| Area | What applies |
|---|---|
| Calabasas | The whole city is a Very High Fire Hazard Severity Zone. Roof assemblies must be Class A, and wood shake and wood shingle roofs, including fire-treated wood, aren’t allowed. |
| Agoura Hills | The whole city is a Very High Fire Hazard Severity Zone. Every reroof must be Class A, and wood shakes aren’t allowed. |
| Malibu | The whole city is a Very High Fire Hazard Severity Zone. The city’s re-roof policy requires Class A materials and prohibits wood shakes and shingles. |
| Hidden Hills | The city requires Class A roofs and doesn’t allow new wood shake roofs. |
| Topanga | Most of Topanga is in a Very High Fire Hazard Severity Zone, where Los Angeles County requires a Class A roof covering. |
| City of Los Angeles hillside areas: Woodland Hills, Tarzana, Encino, West Hills, Chatsworth | Homes in High or Very High Fire Hazard Severity Zones under the state’s 2025 maps need a Class A roof when more than half the roof is replaced. |
| Bell Canyon and Oak Park | Ventura County fire-zone rules apply. We confirm the requirement for your parcel. |
Class A roofing options
Clay and concrete tile
The Mediterranean look common across Calabasas, noncombustible, and Class A in a listed assembly.
Class A shingles
Architectural asphalt shingles, including shake-profile styles, with a Class A rating.
Metal roofing
Standing seam and stone-coated steel, Class A when installed per their listing.
Low-slope systems
Membranes and cap sheets for flat sections, rated as a complete assembly.
See roof replacement, new roof installation, and flat roofing for how we install each one.
Beyond the roof: keeping embers out
Embers carried by wind are a major cause of homes catching fire during wildfires. They don’t need flames to reach the house, only a gap. Under the 2025 California Wildland-Urban Interface Code, new or replaced vents in these fire zones must resist embers and flame. While the roof is open, we also close the other common entry points:
- Replace coarse vent screens with listed ember-resistant vents, or noncombustible, corrosion-resistant mesh with 1/16″ to 1/8″ openings where allowed
- Close the open ends of tile at the eaves with bird stops or eave closures
- Add noncombustible gutter guards and keep gutters clear of leaves and needles
- Use noncombustible materials at roof-to-wall flashing and fascia
Is your home in a fire zone?
CAL FIRE publishes Fire Hazard Severity Zone maps, updated in 2025 for Los Angeles County. Zone boundaries can split neighborhoods, so we check the zone for your parcel before every quote and specify the roof and vents to match.
Frequently asked questions
Do I need a Class A roof if I only replace part of my roof?
It depends on the city and how much of the roof is involved. In Calabasas, any roof repair or replacement needs a permit and the roof must remain a Class A assembly. In City of Los Angeles fire zones, the Class A requirement applies when more than half the roof is replaced. We check the rules for your address before we quote.
Can I get the look of a wood shake roof?
Yes. Concrete tile and some architectural shingles come in shake profiles that keep the rustic look while carrying a Class A fire rating.
Does a Class A roof make my home fireproof?
No roof makes a home fireproof. A Class A roof resists burning embers and flames on the roof itself, but embers can still enter through vents, gaps at the eaves, and debris-filled gutters, which is why we address those too.
Sources
City of Calabasas, “Roof Repair, Replacement & Covering” handout (revised January 2026); City of Agoura Hills reroof handout; City of Malibu residential re-roof policy; Los Angeles County Public Works fire hazard zone notes (2026); Los Angeles Department of Building and Safety fire hazard zone checklist (2026); LAFD on the 2025 CAL FIRE maps. Codes change, so we confirm current requirements on every project. This guide is general information, not legal or engineering advice.