{"id":"cwuic-2025-roof-valley-flashing","license":"CC-BY-4.0","data":{"title":"2025 California WUI Code roof-valley flashing","shortName":"California roof-valley flashing","summary":"The 2025 California Wildland-Urban Interface Code specifies minimum metal thickness and corrosion resistance for valley flashing, over a named cap-sheet detail.","framing":"A flashing product can address the metal portion only. The 36-inch underlayment, full-valley installation, material compatibility, and project details remain separate checks.","kind":"code","instrumentId":"cwuic-2025","jurisdiction":"California mapped fire hazard areas","placeIds":["us-ca"],"appliesToCategories":["roofing"],"quotedText":"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.","source":{"title":"2025 California Wildland-Urban Interface Code, Section 504.2.2","url":"https://mccmeetingspublic.blob.core.usgovcloudapi.net/truckeeca-meet-b4e3431e34524152945f1977841011c4/ITEM-Attachment-001-59998400eff64dacbed9b4337d86e20a.pdf","publisher":"California Building Standards Commission / Town of Truckee public record","sourceType":"official","accessedOn":"2026-08-24T00:00:00.000Z","documentDate":"2025-07-01T00:00:00.000Z"},"constraints":[{"attribute":"assemblyRole","op":"eq","value":"valley-flashing"},{"attribute":"sheetGauge","op":"lte","value":26,"unit":"sheet-gauge"},{"attribute":"corrosionResistant","op":"eq","value":true},{"attribute":"material","op":"in","value":["aluminum","copper","galvanized-steel","stainless-steel","steel","zinc"]}],"relatedStandards":["cwuic"],"author":"grayson-graham","reviewStatus":"draft","lastVerified":"2026-08-24T00:00:00.000Z"},"applications":[{"id":"cwuic-2025-california","title":"California 2025 CWUIC mapped-area application","instrumentId":"cwuic-2025","placeId":"us-ca","status":"active","geographicScope":"mapped-area","scopeSummary":"California applies 2025 CWUIC Chapter 5 to new buildings in mapped State Responsibility Area fire-hazard zones and in locally designated High and Very High zones; the official map, permit facts, any local amendment, and the enforcing agency still govern a project.","effectiveOn":"2026-01-01T00:00:00.000Z","requirementIds":["cwuic-2025-class-a-roof-test-path","cwuic-2025-exterior-glazing-tempered","cwuic-2025-nfpa-252-exterior-door","cwuic-2025-noncombustible-enclosed-open-eave","cwuic-2025-noncombustible-exterior-wall","cwuic-2025-roof-profile-closures","cwuic-2025-roof-valley-flashing","cwuic-2025-sfm-12-7a-1-exterior-door","cwuic-2025-sfm-12-7a-1-exterior-wall","cwuic-2025-sfm-12-7a-3-horizontal-underside","cwuic-2025-astm-e2886-vent","cwuic-2025-one-hour-exterior-wall"],"requirementCoverage":"partial","requirementCoverageSummary":"These 12 rows normalize exact Chapter 5 product semantics that the current catalog can prove. They are not full Chapter 5 normalization; gutters, underfloor enclosure, deck assemblies, accessory structures, alternative glazing and door paths, installation, and local amendments remain outside this cross-section.","requirementScopes":[{"requirementId":"cwuic-2025-class-a-roof-test-path","scopeKeys":["applicable-new-building-in-mapped-area"],"scopeSummary":"This tested roof-assembly path applies only after the official map, permit facts, local amendments, and enforcing agency place the new building within Chapter 5.","sourceSections":["504.2"]},{"requirementId":"cwuic-2025-exterior-glazing-tempered","scopeKeys":["applicable-new-building-in-mapped-area"],"scopeSummary":"This tempered multilayered-glazing path applies only after the official map, permit facts, local amendments, and enforcing agency place the new building within Chapter 5.","sourceSections":["504.8"]},{"requirementId":"cwuic-2025-nfpa-252-exterior-door","scopeKeys":["applicable-new-building-in-mapped-area"],"scopeSummary":"This NFPA 252 exterior-door path applies only after the official map, permit facts, local amendments, and enforcing agency place the new building within Chapter 5.","sourceSections":["504.9"]},{"requirementId":"cwuic-2025-noncombustible-enclosed-open-eave","scopeKeys":["applicable-new-building-in-mapped-area"],"scopeSummary":"This noncombustible eave path applies only after the official map, permit facts, exact eave condition, local amendments, and enforcing agency place the new building within Chapter 5.","sourceSections":["504.3","504.3.1"]},{"requirementId":"cwuic-2025-noncombustible-exterior-wall","scopeKeys":["applicable-new-building-in-mapped-area"],"scopeSummary":"This noncombustible wall path applies only after the official map, permit facts, assembly extent, local amendments, and enforcing agency place the new building within Chapter 5.","sourceSections":["504.5","504.5.2"]},{"requirementId":"cwuic-2025-roof-profile-closures","scopeKeys":["applicable-new-building-in-mapped-area"],"scopeSummary":"This roof-profile closure applies only after the official map, permit facts, roof profile and deck, local amendments, and enforcing agency place the new building within Chapter 5.","sourceSections":["504.2.1.1","504.2.1.2"]},{"requirementId":"cwuic-2025-roof-valley-flashing","scopeKeys":["applicable-new-building-in-mapped-area"],"scopeSummary":"This roof-valley metal path applies only after the official map, permit facts, full underlayment detail, local amendments, and enforcing agency place the new building within Chapter 5.","sourceSections":["504.2.2"]},{"requirementId":"cwuic-2025-sfm-12-7a-1-exterior-door","scopeKeys":["applicable-new-building-in-mapped-area"],"scopeSummary":"This SFM 12-7A-1 exterior-door surface path applies only after the official map, permit facts, exact listed model and installation, local amendments, and enforcing agency place the new building within Chapter 5.","sourceSections":["504.9"]},{"requirementId":"cwuic-2025-sfm-12-7a-1-exterior-wall","scopeKeys":["applicable-new-building-in-mapped-area"],"scopeSummary":"This SFM 12-7A-1 exterior-wall assembly path applies only after the official map, permit facts, exact listed assembly and installation, local amendments, and enforcing agency place the new building within Chapter 5.","sourceSections":["504.5"]},{"requirementId":"cwuic-2025-sfm-12-7a-3-horizontal-underside","scopeKeys":["applicable-new-building-in-mapped-area"],"scopeSummary":"This SFM 12-7A-3 underside path applies only after the official map, permit facts, exact eave or projection condition and listed installation, local amendments, and enforcing agency place the new building within Chapter 5.","sourceSections":["504.3","504.7","504.7.1"]},{"requirementId":"cwuic-2025-astm-e2886-vent","scopeKeys":["applicable-new-building-in-mapped-area"],"scopeSummary":"This ASTM E2886 vent path applies only after the official map, permit facts, exact vent location and listed installation, local amendments, and enforcing agency place the new building within Chapter 5.","sourceSections":["504.10","504.10.1"]},{"requirementId":"cwuic-2025-one-hour-exterior-wall","scopeKeys":["applicable-new-building-in-mapped-area"],"scopeSummary":"This one-hour exterior-side wall path applies only after the official map, permit facts, full listed assembly, local amendments, and enforcing agency place the new building within Chapter 5.","sourceSections":["504.5"]}],"map":{"status":"linked-official-tool","summary":"CAL FIRE's official statewide viewer accepts an address and displays State and Local Responsibility Area fire-hazard zones; the local jurisdiction remains the source for an adopted Local Responsibility Area designation and project decision.","url":"https://experience.arcgis.com/experience/5065c998b4b0462f9ec3c6c226c610a9","source":{"title":"Fire Hazard Severity Zones","url":"https://osfm.fire.ca.gov/what-we-do/community-wildfire-preparedness-and-mitigation/fire-hazard-severity-zones","publisher":"CAL FIRE Office of the State Fire Marshal","sourceType":"official","accessedOn":"2026-08-27T00:00:00.000Z"}},"projectTriggers":[{"summary":"OSFM describes the construction requirements as applying to new buildings with a building-permit application in the named State and Local Responsibility Area fire-hazard zones; repair, replacement, alteration, and local-amendment questions still require the enforcing agency.","sourceSections":["Application Date and Where Required","Ignition Resistant Wildland-Urban-Interface Standards"],"source":{"title":"Building in the Wildland","url":"https://osfm.fire.ca.gov/what-we-do/community-wildfire-preparedness-and-mitigation/building-in-the-wildland","publisher":"CAL FIRE Office of the State Fire Marshal","sourceType":"official","accessedOn":"2026-08-27T00:00:00.000Z"}}],"supportingSources":[{"title":"2025 California Building Standards Code publication and effective date","url":"https://www.dgs.ca.gov/bsc/codes","publisher":"California Building Standards Commission","sourceType":"official","accessedOn":"2026-08-27T00:00:00.000Z","documentDate":"2025-07-01T00:00:00.000Z"},{"title":"Fire Hazard Severity Zones","url":"https://osfm.fire.ca.gov/what-we-do/community-wildfire-preparedness-and-mitigation/fire-hazard-severity-zones","publisher":"CAL FIRE Office of the State Fire Marshal","sourceType":"official","accessedOn":"2026-08-27T00:00:00.000Z"},{"title":"2025 California Wildland-Urban Interface Code construction notes","url":"https://mccmeetingspublic.blob.core.usgovcloudapi.net/truckeeca-meet-b4e3431e34524152945f1977841011c4/ITEM-Attachment-001-59998400eff64dacbed9b4337d86e20a.pdf","publisher":"Town of Truckee public record","sourceType":"official","accessedOn":"2026-08-27T00:00:00.000Z"}],"unresolvedPredicates":["official-hazard-map","project-type","official-confirmation"],"source":{"title":"Building in the Wildland","url":"https://osfm.fire.ca.gov/what-we-do/community-wildfire-preparedness-and-mitigation/building-in-the-wildland","publisher":"CAL FIRE Office of the State Fire Marshal","sourceType":"official","accessedOn":"2026-08-27T00:00:00.000Z"},"author":"grayson-graham","reviewStatus":"draft","lastVerified":"2026-08-27T00:00:00.000Z"}],"products":[{"id":"westlake-royal-ribbed-valley-metal","name":"Westlake Royal ribbed valley metal","url":"/materials/westlake-royal-ribbed-valley-metal/","categories":["roofing"],"complianceStatus":"attribute-match","documentedAttributes":[{"attribute":"assemblyRole","value":"valley-flashing","source":{"title":"Ribbed valley metal","url":"https://www.westlakeroyalbuildingproducts.com/roofing/westlake-royal-roofing-components/ribbed-valley-metal","publisher":"Westlake Royal Roofing LLC","accessedOn":"2026-08-24T00:00:00.000Z","sourceType":"manufacturer"},"documentLocation":null,"excerpt":null},{"attribute":"material","value":"galvanized-steel","source":{"title":"Ribbed valley metal","url":"https://www.westlakeroyalbuildingproducts.com/roofing/westlake-royal-roofing-components/ribbed-valley-metal","publisher":"Westlake Royal Roofing LLC","accessedOn":"2026-08-24T00:00:00.000Z","sourceType":"manufacturer"},"documentLocation":null,"excerpt":null},{"attribute":"sheetGauge","value":26,"source":{"title":"Ribbed valley metal","url":"https://www.westlakeroyalbuildingproducts.com/roofing/westlake-royal-roofing-components/ribbed-valley-metal","publisher":"Westlake Royal Roofing LLC","accessedOn":"2026-08-24T00:00:00.000Z","sourceType":"manufacturer"},"documentLocation":null,"excerpt":null},{"attribute":"corrosionResistant","value":true,"source":{"title":"Ribbed valley metal","url":"https://www.westlakeroyalbuildingproducts.com/roofing/westlake-royal-roofing-components/ribbed-valley-metal","publisher":"Westlake Royal Roofing LLC","accessedOn":"2026-08-24T00:00:00.000Z","sourceType":"manufacturer"},"documentLocation":null,"excerpt":null}]}],"matchContract":"Products appear only when their cited fields satisfy this requirement's normalized constraints. Application scope and unresolved predicates remain separate; an attribute match is not a permit decision."}