Class A is the highest fire rating a roof assembly can earn. In Pasadena it is not required on every home. Pasadena's own ordinance sets a lower floor for every roof in the city.
Stricter state rules attach to mapped fire hazard severity zones and to certain kinds of work. So the rule turns on two questions about your address and your project. Where does your home sit on the City of Pasadena fire hazard severity zone map?
The second question is scope: how much of the existing roof covering will the job replace? That percentage decides whether the state code raises the required class.
This guide walks through the current rules in plain language, with the official sources named. We cannot decide your parcel or approve a product, but we can show you the exact wording. We also point you to the City and the code text where you can check the rule yourself.
What a Class A roof rating covers
Class A describes a tested roof assembly, not a single product, and it rates above Class B. The state code calls for Class A assemblies in mapped fire hazard severity zones.
Labs test those assemblies under ASTM E108 or UL 790. The code also requires an install that follows the listing and the manufacturer instructions. So the way a crew installs the assembly matters as much as the product name.
The class covers the whole assembly, not just the layer you see. A tested assembly usually includes four parts.
- The roof deck that carries the load.
- The underlayment that the listing names.
- The exterior covering you see from the street.
- The install that follows the listing.
A shingle sold as Class A does not carry that rating on its own. Ask which tested assembly the shingle belongs to, then check that the assembly suits your deck and slope.
Pasadena starts at Class B, not Class A
Pasadena adopted the 2025 California Wildland-Urban Interface Code, and that adopting ordinance also amended the state roof class rule. Under that local amendment, a roof assembly in Pasadena must be at least Class B.
The same local text bars wood roof covering in the city's Moderate, High, and Very High fire zones. In the Moderate zone only, the fire code official may approve fire-resistive wood in a listed Class A assembly. That approval covers repair or maintenance of an existing structure, needs good cause or necessity, and may require added mitigation.
So a citywide Class A claim is wrong, because Class B is the floor in Pasadena. Class A attaches through the mapped rules and the scope rules described below.
The local floor and the state trigger do two different jobs. The floor is the lowest roof class Pasadena allows, and the trigger decides when the code requires Class A.
Where the Class A mapped rules apply
The approved state emergency terms set the area where those rules apply. They cover land in a local responsibility area that the State Fire Marshal marks High or Very High. They also cover land that local agencies designate High or Very High.
Locally designated wildland urban interface areas count too, and both High and Very High matter here. The rule is not limited to Very High land alone.
Local designations carry weight here, not only the state map. A city can designate its own High or Very High land.
Pasadena adopted its own fire zone map by ordinance, dated March 24, 2025. Find that map through the City of Pasadena fire hazard severity zones page, then look up your address. We do not decide a zone for you, and the City map is the record.
Map lines can run through the middle of a block. If the address sits near an edge, ask the City to confirm the zone in writing. A written answer from the City is a record you can keep with the permit file.
Pasadena sits in Los Angeles County, and the state sets the wildfire code the city adopts. Altadena, just north of the city line, is unincorporated county land, so Pasadena's rules stop there.
The reroof trigger in the current state code
The code section on existing roofs draws a clear line. Replace the roof covering, and the new covering must meet the new construction rule. The same applies when 50 percent or more is replaced within a 12-month period.
In a mapped fire zone, that new construction rule means a Class A assembly. The scope of the covering work decides whether that rule applies to your job.
The same section carries a second rule. Portions of a covering applied during an addition, alteration, or repair must meet at least a Class A fire classification. That rule stands on its own, inside the scope the code covers.
Measure the covering area before the work starts, and write the number down. Keep that measurement with the permit file, because the percentage decides which rule applies.
Timing matters as well, because the wording covers a 12-month period. Staged work needs the same math, so ask the City how it counts your stages.
You can read the chapter yourself in the current California Wildland-Urban Interface Code, Chapter 5. If a reroof is on your list, call us and we can talk the scope through.
Planning the work around the rule
Scope decides a lot here, so settle it early in the project. A full tear-off and reroof in a mapped zone falls under the new construction rule. A patch or a partial reroof needs the covering measure checked first.
Check the zone early, because finding out late can change the assembly.
Tile work raises the same question. A lift and relay with new underlayment still needs the measure and the listing checked.
Material choice comes after the assembly question. Whether you weigh asphalt shingles, tile, or standing seam metal, ask for the listing behind the product. The assembly listing states the class, so ask us for that document.
We help you pull the required roofing permit from the city with jurisdiction. We do not promise an approval, a schedule, or a result. The City decides that, and the City map decides the zone.
What this article does not settle
We cannot tell you which zone holds your parcel. The City map shows the mapped subareas, and your address either sits inside one or outside it. Look the address up before you plan the work, because the result decides which rules apply.
A neighbor's zone may not match yours, even on the same street. Zone boundaries follow the mapped lines, so two homes on one street can fall differently.
We also cannot give legal advice or approve a product for a permit. Those calls belong to the City and to the tested assembly listing.
How to confirm the rule for your property
A short check before the work saves rework later.
- Look up the address on the City of Pasadena fire zone map.
- Write down how much of the covering the work will replace.
- Ask whether the job counts as a repair, an alteration, or a replacement.
- Ask the City to confirm the roof class for the permit.
- Ask us for the tested assembly listing, not just a product name.
- Keep the current code wording in the project file.
Questions Pasadena owners ask us
Does replacing 25% of a roof trigger the current California rule?
Not as a current state percentage. The code section on existing roofs uses a different measure. It applies when the covering is replaced, or when 50 percent or more is replaced within a 12-month period.
Two cautions still apply. The same section separately asks for at least Class A on portions applied during an addition, alteration, or repair. Pasadena's own rules sit on top, so smaller work still needs a project check.
Does every Pasadena roof have to be Class A?
No, the city ordinance sets a Class B floor and bars wood covering in Moderate, High, and Very High zones. The fire code official may approve fire-resistive wood inside a listed Class A assembly, only in the Moderate zone. That option needs repair or maintenance of an existing structure, good cause or necessity, and possibly added mitigation.
The state code and the mapped fire zone rules can require Class A above that floor. Whether it applies depends on the map and on the job. Check the City map for the address, then confirm the rule with the City.
Talk the scope through before the work starts
Send us the address and the scope, and we can walk through assembly options. We will not guess your zone, and we will not promise a permit outcome.
Bring the code wording with you when you call. We can talk through assemblies, underlayment, and how scope changes the class. Then you can confirm the last word with the City.
Pasadena Roofing Contractors
Pasadena CA
(626) 240-1360