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Which decking is actually approved in a California fire zone
- 2 days ago
- 8 min read
If your property sits in a fire hazard severity zone, your deck boards aren't a matter of taste. They're a compliance item, and they're the one homeowners get wrong most often. Usually it's because a product page said "Class A" and that sounded like the end of it.
It isn't. Here's how the rule actually works, and how to check any product yourself in about two minutes.
First, find out whether the rule applies to you at all
None of this bites unless your parcel sits in a mapped fire hazard severity zone. Outside one, the walking-surface rule isn't your problem and an ordinary board is a perfectly good deck board. So before you shop for anything, look your own address up: the State Fire Marshal's fire hazard severity zone maps
Two things people get wrong here. The first is assuming a whole town is in or out. Zones follow parcels and terrain, and it's common for one side of a street to be mapped and the other side not. The second is assuming the tier doesn't change anything. It does, and it has been moving. In the City of Los Angeles the Class A roof assembly requirement now reaches High as well as Very High.
Then ask your jurisdiction rather than the internet, because cities amend this code and they don't amend it identically. We've had an engineer in one foothill city report that plain two-inch nominal boards were acceptable there on fire grounds, while Los Angeles County's own 2026 fire hazard notes give five compliance options for a walking surface and plain lumber isn't one of them: LA County Fire Hazard Notes, 2026 code version (PDF)
Both can be true at once. That parcel may sit outside the mapped zone, or that city may have amended the section, or the answer may have been about framing rather than the walking surface. What you shouldn't do is carry somebody else's verbal answer onto your own project. Get it in writing, on the permit or in an email from the plan checker, before it reaches a material schedule. A yes at a counter isn't something you can hand an inspector eight months later.
The test is embers, not flame spread
The requirement that governs a deck walking surface in California is now CWUIC Section 504.7.3.2, in the Wildland-Urban Interface Code that took effect on January 1, 2026. The state's summary of what changed in the 2025 cycle is here: 2025 Title 24 California code changes. It gives several compliance paths. The two that do most of the work in residential jobs both run through a State Fire Marshal standard: SFM 12-7A-4, and SFM 12-7A-4A where the exterior wall covering next to the deck is noncombustible or ignition-resistant.
What that test does is drop burning embers on the deck surface and measure what happens.
That's the important part. In a wildfire, decks aren't usually lost to a wall of flame arriving across the yard. They're lost to embers landing on the walking surface, collecting in gaps and against the wall, and lighting the deck from above hours before or after the fire front passes. The test is built around the thing that actually destroys decks.
"Class A" is a different test. It's a flame-spread classification, ASTM E84 or its equivalents. A real measurement, but not the compliance path for a deck surface in California, and plenty of decking products carry a valid State Fire Marshal listing without ever having taken the Class A test. A product can be entirely legal on your deck without the words "Class A" appearing anywhere.
There's a second piece of vocabulary that gets abused. You'll sometimes see a roof classification quoted at you, ASTM E108 or UL 790, as though it settles a fire question. It doesn't settle this one. And it's different again from a one-hour fire-resistance rating, ASTM E119, which describes how long an assembly holds up rather than how a covering behaves. Three tests, three questions. A salesperson who slides between them without noticing is a salesperson who hasn't read the report.
One more thing worth having straight. The code section describes tests and performance. The reason your plan checker wants a listing number in front of them comes from a separate statute and the listing program built to administer it. In practice the two work as one requirement, and it's why "it meets the standard" is a weaker answer than "here's the listing."
Where the products actually stand
Listings change, so treat this as a snapshot from August 2026 and check before you buy. What doesn't change is the shape of the problem. Listings are product-line specific, and several carry conditions.
TimberTech AZEK, Vintage and Landmark Collections. Both listed Class A with no conditions attached, listings 8110-2042:0001 and 8110-2042:0503. These are the two most straightforward PVC answers for a fire zone right now. TimberTech absorbed AZEK, so the same boards appear under both names. If you have older AZEK on the property and want to match it, that's where to look.
Don't read that as "AZEK passes." It's the collection that's listed, not the brand. AZEK Porch and the Harvest, Arbor and Terra collections are listed Class B, and the TimberTech Pro Reserve lines are Class C with a wall-covering condition. Same manufacturer, four different answers.
Kayu Batu, also sold as Red Balau. Listed Class A with no conditions, listing 8110-2069:0001. If you want a real hardwood deck in a fire zone, this is the least complicated way to get one.
Ipe. Listed, but it depends entirely on the supplier. Mataverde Premium is listed Class A for its Ipe. Redwood Empire's Ipe is listed Class B. Plenty of other suppliers' Ipe was never submitted for testing at all. The board looks identical in every case and the species name tells you nothing. This is the single biggest trap in fire-zone hardwood, and it's why we check the specific supplier before Ipe goes on a material schedule. More on hardwood decking generally: Ipe and hardwood decking
Trex Transcend, Select and Transcend Lineage. Listed, but each carries a condition: the exterior wall covering next to the deck has to be noncombustible or ignition-resistant. That isn't a dealbreaker, it's a design constraint, and it needs settling while the wall assembly is still being decided rather than after. All three are listed with the ASTM E84 flame-spread test not conducted, so you won't find a Class A on them at all. Which is a good illustration of the earlier point. They're compliant products. Class A simply isn't the road they took.
Trex Enhance. Not listed. It's a perfectly good board and we build with it happily in Encino or Sherman Oaks. It will get red-lined on a Palisades permit.
Trex Refuge. Listed Class A, and California-recognized as of this year, listing 8110-2052:0502. This is Trex's ignition-resistant PVC board and it's a good option in a fire zone. California listed it on May 31, 2026 after testing to SFM 12-7A-4A and ASTM E84, for wildland-urban interface use with the exterior wall covering next to the deck meeting CWUIC Section 504.5. The same wall-covering pairing the rest of the Trex fire-zone range carries.
The only thing worth knowing about Refuge is how recent that listing is. The board launched in January 2026 and the California listing followed at the end of May, so anything written before last summer will tell you Trex has no California-listed PVC board. That was true once. It isn't true now.
It's also the clearest example on this page of why the live database beats a printed list. Refuge isn't in the handbook published in September 2025, and it won't be in a spec sheet or supplier binder assembled before June 2026. If somebody waves you off it, look the listing number up rather than taking their word for it.
More on composite and PVC generally: composite and PVC decking
Checking it yourself, in about two minutes
The listings are public. The searchable database is here, and you don't need an account or a contractor to look something up: the State Fire Marshal Building Materials Listing search
Background on how the listing program works: the Office of the State Fire Marshal listing program
There's a printable version too. The State Fire Marshal publishes a WUI Listed Products Handbook with every listed product, its listing number, its classification and its conditions, in one PDF you can hand to a plan checker or an architect: the OSFM WUI Listed Products Handbook
Search the product line, not the brand. "Trex" gets you nothing useful. "Trex Transcend" gets you an answer. Brands sell many lines and only some of them are submitted for testing.
Then read past the word "listed." Some entries carry conditions, and a conditional listing is still a listing. It just means something else on the building has to be true as well. Skipping the conditions is the most common way people arrive at plan check believing they're compliant.
Finally, look at the dates. Entries get renewed, and an expired one isn't much use to you.
Expect one piece of confusion while you're in there. A good deal of the surrounding paperwork, including material published by the state itself, still refers to listings in terms of "Chapter 7A" and "R337," the two chapters that were removed in January 2026. That's documentation catching up, not a contradiction. The listings themselves are unaffected.
The rest of the deck matters too
The code regulates the walking surface, meaning boards and stair treads. It doesn't regulate the framing underneath the same way, which surprises people. But two adjacent requirements catch nearly every fire-zone deck.
Deck-to-wall intersections need a minimum of six inches of metal flashing applied vertically on the exterior of the wall.
Underfloor areas have to be enclosed to grade with compliant construction, and exposed underfloor and projections have to be noncombustible, ignition-resistant, fire-retardant-treated wood, or one-hour rated. On an elevated hillside deck this is often the biggest cost nobody planned for.
Both are spelled out in the LADBS plan-check checklist for fire hazard severity zones, Section G: the LADBS Fire Hazard Severity Zone checklist (PDF)
County and City are not the same rulebook
Unincorporated Los Angeles County, which includes Altadena, didn't adopt the new wildfire code in full. Its own Title 26 amends the relevant chapter selectively. The practical effect is that a material schedule cleared by City plan check isn't automatically one that clears County plan check, and the reverse holds too. Whichever agency holds your parcel, that's the code to read.
And if you've been assuming a High zone is the forgiving version of a Very High zone, that assumption has expired in the City of Los Angeles, where the Class A roof assembly requirement now reaches both. Look up your own zone rather than inheriting somebody's rule of thumb about it.
What is coming
The Board of Forestry signed off on the Zone 0 rules in August 2026. Those govern combustible material within five feet of a structure. As of this writing they're still at the Office of Administrative Law with no effective date set. New construction will comply on approval, and existing structures phase in over several years.
Nobody has to comply yet. But if you're choosing decking now for a deck that sits against the house, the five-foot band around your walls is where the rules are tightening next.
The short version
If you want it simple: TimberTech AZEK Vintage, TimberTech AZEK Landmark and Kayu Batu won't give you an argument at plan check, because none of them carries a condition. Trex Refuge and the rest of the Trex fire-zone range are just as legitimate. They simply come with the wall covering attached to the answer, so that has to be settled at the same time. Everything else needs the specific product line looked up.
We do that check before the proposal goes out, not after the plans come back. If you're in a fire zone and want a straight answer about what will and won't pass, call (818) 345-2866.
If you're rebuilding after the Palisades or Eaton fire, the permitting and code-relief side is covered separately here: rebuilding in the Palisades or Altadena
And what we do on fire-zone builds: fire-zone decking
Danny Deck Construction, building in Los Angeles since 1995. CA License #896848.
Written August 2026. Product listings and fire-zone code are both moving right now. Verify current listings in the State Fire Marshal Building Materials Listing before you buy.
