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2025 California WUI Code roof-valley flashing
The 2025 California Wildland-Urban Interface Code specifies minimum metal thickness and corrosion resistance for valley flashing, over a named cap-sheet detail.
A flashing product can address the metal portion only. The 36-inch underlayment, full-valley installation, material compatibility, and project details remain separate checks.
Published requirement text
“Valley flashings shall be not less than 0.019 inch (0.48 mm) (No. 26 galvanized sheet gage) corrosion resistant metal installed over a minimum 36-inch-wide (914 mm) underlayment.”
Where this instrument is documented
Set a location to read how this instrument lands where you are.
In California, this instrument has an active application record — 3 official checks open. Open the California record
| Place | Force | Reach | Dated | Checks open | Source |
|---|---|---|---|---|---|
| California | active application documented | mapped area | effective 2026-01-01 | 3 | Building in the Wildland |
Machine-readable constraints
| Attribute | Operator | Value | Unit |
|---|---|---|---|
| assemblyRole | eq | valley-flashing | |
| sheetGauge | lte | 26 | sheet-gauge |
| corrosionResistant | eq | true | |
| material | in | aluminum–copper–galvanized-steel–stainless-steel–steel–zinc |
Products with documented matching attributes
| Product | Category | Status | Documented match evidence |
|---|---|---|---|
| Westlake Royal ribbed valley metal | roofing | Attribute match |