Comparison

Aluminum vs. steel vs. chain link: which metal for your 5-foot Zone 0 fence section?

Fact-checked August 19, 2026·Sources at the end of this article

Why you're choosing a metal at all

One sentence of rule text is the reason. California's statewide Zone 0 regulation, approved by the Board of Forestry on August 19, 2026 and not yet in effect, requires a noncombustible section where a fence meets the house:

All fences and gates that are attached to an Occupied Structure, or come within one (1) foot of contact with an Occupied Structure, shall have a five (5) foot Noncombustible span from the point of attachment or the point closest to the Occupied Structure.

Board of Forestry, Zone 0 regulation §1298.04(b)(9)(A), the Local Responsibility Area text; wording unchanged from the July 2026 draft in the package approved August 19, 2026.

The State Responsibility Area track carries the same span requirement at §1299.03(d)(9), but it is not word-for-word the same provision: it runs as a single undivided paragraph and is phrased around a "Building or Structure" rather than an "Occupied Structure." Quote the track that covers your address. Two caveats on wording generally: the package we read is the pre-meeting deliberative draft, so any amendment made from the floor would not appear in it, and no certified "as adopted" text has been published yet.

The insurance side is already in force and has been since October 14, 2022. Under the "Safer from Wildfires" regulation (10 CCR §2644.9), insurers that price California homeowners policies on wildfire risk must offer a rating credit for, among other measures:

Incorporation of only noncombustible materials into that portion of any improvements to the property on which the Building Being Evaluated is located, including fences and gates, which is situated within five (5) feet of the Building Being Evaluated.

10 CCR §2644.9(d)(1)(B)1.c.

Both texts turn on one word: noncombustible. Neither ranks one metal above another. If you are still deciding whether this applies to your fence at all, start with the full Zone 0 fencing guide; if you already know you need the span, this article is the materials decision.

The test all three pass

The regulation defines "Noncombustible" as materials that pass ASTM E136, a vertical tube furnace test at 750 °C that measures whether the material itself can burn or add fuel. In practice, the materials that pass are aluminum, steel, wrought iron, chain link, masonry, concrete, and stone. Wood, vinyl, composite, and fire-retardant treated wood do not pass.

The voluntary IBHS Wildfire Prepared Home standard reads the same way. Its checklist for the 0–5 foot zone allows metal (aluminum, steel, chain link, iron) or concrete only, and states plainly:

All fencing materials within the 0–5 Foot Noncombustible Zone (Zone 0) must be noncombustible.

IBHS Wildfire Prepared Home Technical Standard (updated June 17, 2025).

One honest caveat that applies to every product on the market: no fence-assembly fire test exists in US code. ASTM's fencing committee maintains no fire test for fence assemblies, and California's State Fire Marshal Building Materials Listing has no fence category. So no manufacturer can truthfully sell you a "certified fire-resistant fence." What you can verify is simpler and better: whether the material itself is noncombustible. All three metals here are. For the longer list of what passes and fails, see noncombustible fence materials.

The comparison at a glance

Fire performance under the regulation's definition is a pass/fail question, and all three pass, so the real comparison is practical. No prices here, because fabrication, height, gates, and site work swing costs too much for a generic number to be honest.

How the three metals differ in practice

Aluminum: light and rust-free

Aluminum's case is handling and maintenance. It is the lightest of the three, which matters twice: panels are manageable for one person during installation, and gates built from it put less strain on hinges and posts over years of swinging. It does not rust, which makes it a low-worry choice near irrigation spray, at the coast, or anywhere you don't want to think about touching up a coating. The trade-off is that aluminum panels are typically open picket designs. They read as ornamental fencing and give little privacy.

Steel: heavier and more substantial

Steel is the heavier, more rigid option. If you want the 5-foot span to feel like a solid, permanent piece of the property, or you're hanging a wide or heavy gate at the house corner, steel's stiffness is the argument for it. The trade-off is corrosion care: steel depends on its protective coating, and where that coating gets scratched or chipped, the metal underneath can corrode. That is a maintenance consideration. It has no bearing on the fire question; steel is among the materials that pass ASTM E136.

Chain link: the galvanized utility option

Chain link is galvanized steel wire (zinc-coated for corrosion protection) on a light pipe framework. It is the least decorative of the three and the most familiar to do-it-yourselfers, and gate frames are a standard part of the system. One caution: chain link is see-through, and if you want privacy, resist the urge to weave plastic slats through the 5-foot span. Vinyl does not pass ASTM E136, so combustible slats would undo exactly what the noncombustible span is for. On looks, chain link's plainness carries no compliance penalty: the IBHS checklist names it right alongside aluminum and steel.

The non-metal path: masonry, concrete, and stone

If none of the metals suits the spot, or you want the privacy that metal fencing doesn't give you, masonry, concrete, and stone also pass ASTM E136. A short masonry or concrete wall section where the fence meets the house is the noncombustible way to keep a visual screen in the first five feet. It is the heaviest option and the most likely to involve a contractor and a footing, but it is the only path here that is both noncombustible and opaque.

Decision guide by situation

Whichever way you go, the geometry is the same: a 5-foot noncombustible span at the point of attachment, with the rest of the fence untouched. The five-foot transition guide walks through how the span meets an existing wood run.

What this means for you

As of August 19, 2026, the statewide rule is adopted but not yet in effect. The Board of Forestry approved it that day, and the package still has to clear Office of Administrative Law review, including a five-day public comment period, before the Secretary of State publishes it. Once an effective date exists, existing homes will have years, not weeks, for fence work; only new construction has to comply on the effective date itself. The Board's own staff put it this way in their July 2026 memo: "The purpose of the regulations is not to require wholesale replacement of existing wood fences." So there is time to make this decision carefully. Practical points:

• Any of the three metals does the job. Installing one now meets the requirement in the adopted regulation ahead of its effective date, and it meets the §2644.9 noncombustible-materials measure today. The fencing item appears first among the measures on carrier mitigation forms. See how the fence insurance credits work; carrier-published discount figures are theirs, not promises.
• Check the whole assembly, not just the panel. A metal panel on a wood post fails the intent. Look at the posts, the footing, gate hardware and latches, and any wood blocking where the fence attaches to the wall.
• Skip combustible add-ons in the span. Vinyl privacy slats, wood cap rails, and composite infill do not pass ASTM E136.
• Ignore "fire-rated fence" marketing. No fence-assembly fire test exists, so that phrase has nothing behind it. "Class A" ratings come from ASTM E84, an interior-finish test, not a substitute for noncombustible.
• Work through the rest of the zone while you're at it. The fence span is one item; the Zone 0 checklist covers the full first five feet.

The California Department of Insurance's framing is a useful north star for why the span matters regardless of which metal you choose: "Replacing wood fencing connecting to your home with metal is critical because it can act like a candle wick leading fire straight to your home."