Wildfire-Resistant Metal Roofing & Siding: What Idaho & Montana Homeowners Need to Know

If you live in North Idaho, Western Montana, or Eastern Washington, wildfire risk isn’t an abstract concern — it’s a factor in nearly every building decision, from defensible space around your home to the materials on your roof and walls. Embers don’t just target the roof; they collect in eaves, land on siding, and work into any combustible surface they can reach. That’s why building codes in wildfire-prone areas address the whole exterior envelope — roofing and siding — not just the roof.

Metal sits at the top of the list of fire-resistant materials for both, and for homeowners and builders working in or near a Wildland-Urban Interface (WUI) zone, understanding why — and what it actually takes to meet code on each — matters as much as picking a color.

Why Metal Roofing and Siding Perform Well in Wildfire Conditions

Steel doesn’t ignite. Unlike asphalt shingles, wood shakes, or wood siding, metal panels won’t catch fire from a landed ember, and they won’t contribute fuel if a fire does reach your property — whether that panel is on the roof or the wall. That’s the core reason metal shows up again and again in wildfire-mitigation guidance for mountain and forested communities — see NFPA’s guidance on preparing homes for wildfire for more on how embers ignite homes.

That said, “metal” isn’t automatically a complete fire-rated assembly on either surface. Fire ratings apply to the whole system — panel, underlayment or sheathing, and deck or framing — not just the top layer.

Understanding Fire Ratings: Roofs vs. Siding

These two parts of your home are actually governed by different code sections, so it’s worth knowing the difference:

Roofing is tested and classified under ASTM E108, Standard Test Methods for Fire Tests of Roof Coverings, into three tiers, with Class A offering the highest level of fire resistance. Steel and other ferrous metal roof panels are recognized in code as Class A materials, provided they’re installed as part of a compliant assembly — typically over a noncombustible deck or with a fire-rated underlayment, per the Wildland-Urban Interface Code roofing requirements that most western fire hazard zones reference.

Siding and exterior wall coverings fall under a separate set of requirements — in Montana, for example, Chapter 5 of the Wildland-Urban Interface Code requires exterior wall coverings in designated fire hazard zones to be noncombustible or ignition-resistant. Steel siding qualifies as a noncombustible material in the same way steel roofing does — but as with roofing, the exact assembly (sheathing, furring, insulation behind it) can affect whether a given install meets your specific zone’s requirements.

This is the detail that trips people up: the panels themselves are inherently fire-resistant, but meeting code in a High or Very High Fire Hazard Severity Zone depends on the full assembly on both the roof and the walls. If you’re building or re-roofing/re-siding in a designated WUI zone in Idaho or Montana, this is worth confirming with your local building department or your contractor before panels go on order.

What This Means for Your Panel Choice

Ibex Metal manufactures panel profiles for both applications from the same noncombustible steel base. On the roofing side, that includes Tuff-Rib, PBR, and standing seam Snap-Lock and Mechanical-Lock profiles; on the siding side, 10″ and 16″ Board & Batten, Flush Mount, and Corrugated — with Corrugated also commonly used as a roofing panel. The profile you choose comes down to look, budget, and structure type rather than fire performance; the fire resistance comes from the material itself, on either surface.

That’s a meaningful difference from wood shake roofing or wood siding, where the only way to improve fire performance is to add fire-retardant treatments that degrade over time. Steel’s fire resistance doesn’t wear off, whether it’s overhead or on the wall.

Beyond the Basics: Reducing Ember Risk at Every Surface

Roofing and siding are the biggest pieces of the puzzle, but wildfire-hardening a home usually includes a few related details worth planning for at the same time:

• Soffit and eave protection — embers collect in vented eaves; metal soffit panels close off that entry point compared to open or vinyl soffits
• Gutter debris — combustible leaf and needle buildup in gutters is a common ignition point regardless of roof material
• Wall-to-roof and wall-to-ground transitions — gaps at valleys, chimneys, and where siding meets grade are common ember entry points if not properly detailed
• Accent and trim details — matching metal trim at corners, window/door surrounds, and transitions keeps combustible wood trim from undermining an otherwise noncombustible wall assembly

Talk to a Local Team Who Understands the Terrain

Ibex Metal manufactures roofing and siding panels in Bonners Ferry, Idaho, and we work with contractors and homeowners across North Idaho, Western Montana, and Eastern Washington — communities where wildfire planning isn’t optional. If you’re planning a re-roof, new siding, or new build in a WUI zone, contact us to talk through panel options, or order free color samples to see finishes in person before you commit.

FAQ

Is metal roofing automatically Class A fire rated?

The panel material itself is noncombustible, but a full Class A rating (per ASTM E108/UL 790) depends on the complete roof assembly — including underlayment and deck. Confirm the assembly requirements for your specific fire hazard zone with your local building department.

Does metal siding meet wildfire code the same way metal roofing does?

Metal siding is a noncombustible material, which generally satisfies wildfire code requirements for exterior wall coverings, but siding is governed by a different code section than roofing (ignition-resistant construction rules rather than the ASTM E108 roof-covering classes). Confirm the specific requirements for your fire hazard zone with your local building department.

Do metal roofs and siding increase or decrease home insurance costs in wildfire zones?

Many insurers offer reduced premiums or are more willing to write policies for homes with Class A-rated roofing and noncombustible siding in high fire-risk areas, though specifics vary by carrier and state. Check with your insurance provider directly, as this isn’t something a roofing manufacturer can guarantee.

Can embers still cause damage even with metal roofing and siding?

Metal won’t ignite, but embers can still collect in gutters, vents, open eaves, and gaps at wall transitions. Pairing metal roofing and siding with metal soffit panels, proper flashing, and clean gutters closes off most of the remaining ember entry points.

Does panel profile affect fire performance?

No — fire resistance comes from the steel itself, not the profile, on either roofing or siding panels. Profile choice is a matter of aesthetics, budget, and structural fit, not fire rating.

How long does the fire resistance of metal roofing or siding last?

Unlike fire-retardant treatments on wood shakes or wood siding, which degrade over time and require reapplication, steel’s noncombustibility doesn’t diminish with age.