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2021 IWUIC Class 1 and 2 noncombustible exterior-wall path

The unamended 2021 IWUIC includes approved noncombustible material as an exterior-wall path in Class 1 and Class 2 construction.

This record covers only the product material path. Approval, full wall construction, foundation-to-roof extent, other alternatives, official class, project scope, and local amendments remain checks.

code · Jurisdictions adopting unamended 2021 IWUIC Chapter 5 · Last verified 2026-08-27 · JSON (CC BY 4.0)

Published requirement text

“Approved noncombustible materials.”

2021 International Wildland-Urban Interface Code, Sections 504.5 and 505.5 — International Code Council

Where this instrument is documented

Instrument iwuic-2021.

Set a location to read how this instrument lands where you are.

Place	Force	Reach	Dated	Checks open	Source
Pennsylvania	active application documented	statewide	effective 2026-01-01	4	34 Pa. Code § 403.21 Uniform Construction Code

Each place page carries that place's boundary, project scope and open official checks in full; this page's JSON twin carries them per application.

Machine-readable constraints

Attribute	Operator	Value
noncombustible	eq	true

Products with documented matching attributes

Open the Build rules that quote this requirement

Product	Category	Status	Documented match evidence
AL13® Plank System	siding	Listed	1 cited field Noncombustible: Yes
Clicklad Closed-Gap aluminum cladding system	siding	Listed	1 cited field Noncombustible: Yes
Hardie® Plank lap siding	siding	Listed	1 cited field Noncombustible: Yes
Hardie® Textured Panel, noncombustible fiber-cement panel siding, 5/16" thick	siding	Listed	1 cited field Noncombustible: Yes · Listing 8140-2026:0502, Description field
JAMES HARDIE BUILDING PRODUCTS, INC. (8140-2026:0001)	siding	Listed	1 cited field Noncombustible: Yes
JAMES HARDIE BUILDING PRODUCTS, INC. (8140-2026:0004)	siding	Listed	1 cited field Noncombustible: Yes
JAMES HARDIE BUILDING PRODUCTS, INC. (8140-2026:0500)	siding	Listed	1 cited field Noncombustible: Yes
Longboard® 6-inch exterior aluminum siding	siding	Listed	1 cited field Noncombustible: Yes
ROCKWOOL Comfortboard 80 exterior continuous insulation	siding	Listed	1 cited field Noncombustible: Yes
Thermafiber RainBarrier High Compressive 80 and 110 exterior insulation	siding	Listed	2 cited fields Noncombustible: Yes Noncombustible: Yes
WoodSyn OptimBoard™ wood-wool cement sheathing	siding	Listed	1 cited field Noncombustible: Yes

Sources

2021 International Wildland-Urban Interface Code, Sections 504.5 and 505.5 — International Code Council (official). Accessed 2026-08-27.

2021 IWUIC Class 1 and 2 noncombustible exterior-wall path. FireApproved. https://fireapproved.com/requirements/iwuic-2021-class-1-2-noncombustible-exterior-wall/. Last verified 2026-08-27.