Home / Requirements / 2021 IWUIC valley flashing

2021 IWUIC roof-valley flashing metal path

The unamended 2021 IWUIC specifies No. 26 galvanized corrosion-resistant metal valley flashing over a named full-width cap-sheet detail.

A flashing product can document the metal portion only. The 36-inch cap sheet, full-valley installation, compatibility, official class, project scope, and locally adopted text remain checks.

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

Published requirement text

“not less than 0.019 inch (0.48 mm) (No. 26 galvanized sheet gage) corrosion-resistant metal”

2021 International Wildland-Urban Interface Code, Sections 504.2.1, 505.2.1, and 506.2.1 — 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	Unit
assemblyRole	eq	valley-flashing
sheetGauge	lte	26	sheet-gauge
corrosionResistant	eq	true
material	in	galvanized-steel

Products with documented matching attributes

Open the Build rules that quote this requirement

Product	Category	Status	Documented match evidence
Westlake Royal ribbed valley metal	roofing	Attribute match	4 cited fields Assembly role: valley flashing Material: galvanized steel Sheet gauge: 26 Corrosion resistant: Yes

Sources

2021 International Wildland-Urban Interface Code, Sections 504.2.1, 505.2.1, and 506.2.1 — International Code Council (official). Accessed 2026-08-27.

2021 IWUIC roof-valley flashing metal path. FireApproved. https://fireapproved.com/requirements/iwuic-2021-roof-valley-flashing/. Last verified 2026-08-27.