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Building Code Reference

Got a CRC R902.1 correction?

Class A roof covering

For builders in California, Greater Seattle, the Las Vegas area, the Denver area and Kansas City · CrossBeam Permits

What this code requires, how to fix it, and how cities and counties review it

What this code requires

CRC R902.1 is the California Residential Code section that sets the minimum fire-resistance classification for roof coverings on new residential construction. Outside Fire Hazard Severity Zones and Wildland-Urban Interface areas, California requires at least a Class C roof covering on new homes. Inside those areas, the California Wildland-Urban Interface Code requires a Class A roof assembly, so Class B and C coverings are not allowed there. The roofing material, product name, and its UL or ASTM E108 classification must be called out explicitly on the plans.

How to fix it

  1. Confirm your project's fire hazard zone designation

    Go to the Cal Fire FHSZ viewer at osfm.fire.ca.gov or check your city’s GIS portal. If the project parcel falls inside a Fire Hazard Severity Zone (State or Local Responsibility Area) or a Wildland-Urban Interface area, note that designation. You will need to reference it on your plans. If you are outside those areas, CRC R902.1.2 requires at least a Class C roof covering, and you don’t need the zone note on the cover sheet.

  2. Choose a listed roof covering of the required class

    In a Fire Hazard Severity Zone or WUI area, California Wildland-Urban Interface Code Section 504.2 requires a Class A roof assembly tested to ASTM E108 or UL 790. Nearly all asphalt fiberglass shingles made today are Class A — but you must verify with the manufacturer’s product data sheet. Look for the UL or ASTM classification on the product label or the ICC Evaluation Service (ICC-ES) report. Metal, concrete tile and clay tile count as Class A without testing only on noncombustible roof decks; on wood decks, use a listed Class A assembly. Wood shakes must be fire-retardant-treated products listed under R902.2.

  3. Add a roof covering note to the plans

    On the roof plan sheet and/or the general notes sheet, add a note that includes: (1) the manufacturer name and product line, (2) the fire classification (Class A), and (3) the UL or ASTM classification number or ICC-ES report number. Example note: "Roof covering: CertainTeed Landmark AR, Class A per UL 790, ICC-ES ESR-1389. Installed per manufacturer instructions and CRC R905." That level of specificity is what plan checkers need to sign off without a correction.

  4. Add the fire hazard zone note if in VHFHSZ or HFHSZ

    If your parcel is in a designated fire hazard zone, add a separate note near the project data block on the cover sheet: "Project located in [Very High / High] Fire Hazard Severity Zone per Cal Fire designation. Roof covering is Class A per CRC R902.1.1 and CWUIC 504.2." Some plan checkers will also want to see the APN, the zone boundary reference, or a printed Cal Fire map exhibit attached to the drawings. Check with your specific jurisdiction before resubmitting.

  5. Reference the ICC-ES or UL listing on the spec sheet

    Attach the product data sheet or ICC-ES report as a reference exhibit in the plan set, or reference it by report number in the notes. The ICC-ES reports are publicly available at icc-es.org. The UL product certification database at iq.ul.com also works. Either reference confirms that the product holds the stated classification independent of the manufacturer’s marketing claims.

  6. Update plans immediately if material changes on-site

    If you substitute roof covering products after the plans are approved, submit a minor change or field change request to the building department before the material goes on. Switching from a named Class A product to a different Class A product still requires a plan revision showing the new product name and its classification. This avoids an R902.1 correction at inspection that forces a stop-work order until you get a field change approved.

  7. Verify underlayment and flashing also meet CRC R905

    CRC R902.1 covers the covering classification. CRC R905 covers installation requirements including underlayment type, fastening pattern, and flashing details. Plan checkers often flag both sections together on the same correction letter. Make sure your roof plan notes the underlayment (e.g., "synthetic underlayment, ASTM D8257") and that flashings are called out at valleys, penetrations, and eave edges. Getting R902.1 right while missing R905 details just results in two separate correction cycles.

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Why you got flagged

Plan checkers flag CRC R902.1 for a handful of predictable reasons, and most of them come down to the same root cause: the roof covering specification is either missing from the plans or too vague to confirm compliance.

The most common hit is a simple omission. The plans call out framing, sheathing, and underlayment — but nowhere does a note on the roof plan or general notes sheet state the actual product name and its fire classification. "Asphalt shingle roof" gets flagged. "CertainTeed Landmark Class A" passes. Plan checkers cannot verify what’s not written down, and they won’t approve it on good faith.

A second common scenario involves properties inside a VHFHSZ. Cal Fire’s mapping shows roughly the northern hills of Anaheim and many Irvine canyon-facing lots in designated Very High zones. If the project is in one of those zones, the plan set needs to explicitly note both the zone designation and the Class A compliance. Reviewers scan for this note first — if it’s absent, the correction lands on the letter regardless of whether the specified product is actually Class A.

The third scenario is a material substitution without a matching spec update. A contractor switches from the specified shingle to a composite or metal panel mid-project for budget reasons. The product on-site is Class A, but the approved plans reference the original spec. The field inspector flags it as not-per-plans, and now R902.1 shows up in the correction letter even though the new material technically passes.

The official code

CRC R902.1 — California Residential Code, Chapter 9 Roof Assemblies

Read the source →

Common questions

Does CRC R902.1 apply to a reroof on an existing house?
A permit-required reroof on an existing home in California generally must bring the roof covering up to current code: Class A inside a Fire Hazard Severity Zone or WUI area, and at least Class C elsewhere under R902.1.2 when more than half the roof is replaced in a year. If you are adding a second layer over an existing roof (where permitted), check with your jurisdiction — some cities require you to match the new material to Class A regardless. Under R902.1.2, any roof covering applied in an alteration, repair or replacement must also meet the class requirement. When in doubt, ask the plan checker before you submit — they’d rather answer a quick question than write a correction.
What's the difference between a Class A and Class B roof covering?
The fire classification rates how well the roof covering resists spread of flame and penetration from an exterior fire source. Class A is the highest rating and is required in Fire Hazard Severity Zones and WUI areas. Class B coverings resist moderate fire exposure but can still allow flame penetration after 4 minutes of direct flame. Class C is the lowest rated category. Outside those areas, CRC R902.1.2 allows any roof covering of at least Class C. The classification comes from testing per UL 790 or ASTM E108.
Are all asphalt shingles automatically Class A?
Most modern fiberglass-mat asphalt shingles are Class A — but not all. The classification depends on the specific product and how it was tested. Organic-mat asphalt shingles (older style, mostly phased out) are sometimes rated Class C. Never assume the rating from the material type alone. Check the product label, the manufacturer’s data sheet, or the ICC-ES evaluation report for the specific product you’re using. The ICC-ES reports list the exact UL 790 or ASTM E108 classification.
My project is in a fire hazard zone — does R902.1 add extra requirements?
In a Very High Fire Hazard Severity Zone (VHFHSZ) or High Fire Hazard Severity Zone (HFHSZ), CRC R902.1.1 sends you to the California Wildland-Urban Interface Code, which requires a Class A roof assembly (Section 504.2). But the plans must explicitly note the zone designation and the compliance statement. The same code, which replaced the old CRC R337 provisions, adds requirements for vents, eave protection, and siding in addition to the roof. If your parcel is in a mapped zone, roof and WUI corrections often show up together on the same letter.
Can I use wood shakes on a new house in California?
Only fire-retardant-treated shakes listed under CRC R902.2 and approved by the State Fire Marshal, rated for the class your site requires: Class A in a Fire Hazard Severity Zone or WUI area, at least Class C elsewhere. There are treated wood shake products that achieve Class A through fire-retardant treatment and tested assembly — but they are uncommon and expensive. Most plan checkers flag untreated or standard wood shakes immediately. If you’re going for a shake look, consider Class A-rated shake-profile asphalt or composite shingles that pass without issues.
The plan checker flagged my spec sheet reference — what exactly do they need?
Plan checkers want a specific product name, the fire classification, and a reference to the testing standard or listing report — all in a note directly on the plans, not just in a separate attached document. A general note that says "roofing per Title 24" is not enough. Write it out: manufacturer, product line, Class A, UL 790 or ASTM E108, and optionally the ICC-ES report number. If you also attach the product data sheet as an exhibit, reference it in the note (e.g., "see Exhibit R1"). That combination is what plan checkers need to check the box.

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