{"id":"iwuic-2021-class-3-class-b-roof-assembly","license":"CC-BY-4.0","data":{"title":"2021 IWUIC Class 3 Class B roof-assembly path","shortName":"2021 IWUIC Class 3 Class B roof","summary":"The unamended 2021 IWUIC specifies a Class B-or-better tested roof assembly for Class 3 ignition-resistant construction.","framing":"A documented roof assembly can match the minimum rating and test. The alternative approved noncombustible covering, deck, underlayment, profile-space, official class, project scope, and local amendments remain separate checks.","kind":"code","instrumentId":"iwuic-2021","jurisdiction":"Jurisdictions adopting unamended 2021 IWUIC Chapter 5","appliesToCategories":["roofing"],"quotedText":"not less than a Class B rating when tested in accordance with ASTM E108 or UL 790","source":{"title":"2021 International Wildland-Urban Interface Code, Section 506.2","url":"https://codes.iccsafe.org/content/IWUIC2021P2/chapter-5-special-building-construction-regulations","publisher":"International Code Council","sourceType":"official","accessedOn":"2026-08-27T00:00:00.000Z"},"constraints":[{"attribute":"assemblyRole","op":"eq","value":"roof-assembly"},{"attribute":"fireRating","op":"in","value":["class-a","class-b"]},{"attribute":"testStandard","op":"in","value":["astm-e108","ul-790"]}],"relatedStandards":["iwuic","astm-e108-ul-790"],"author":"grayson-graham","reviewStatus":"draft","lastVerified":"2026-08-27T00:00:00.000Z"},"applications":[{"id":"iwuic-2021-pennsylvania","title":"Pennsylvania Uniform Construction Code incorporates IWUIC 2021","instrumentId":"iwuic-2021","placeId":"us-pa","status":"active","geographicScope":"statewide","scopeSummary":"34 Pa. Code § 403.21(a)(11) adopts and incorporates by reference the International Wildland-Urban Interface Code of 2021 as part of the Uniform Construction Code. The November 7, 2025 amendment is effective January 1, 2026, and the State's final report says the 2021 IWUIC was adopted without modification. Whether a given lot is in a wildland-urban interface, which ignition-resistant class applies, and whether a given project type is in scope still depend on the official map and the building official.","effectiveOn":"2026-01-01T00:00:00.000Z","requirementIds":["iwuic-2021-class-1-2-20-minute-exterior-door","iwuic-2021-class-1-2-class-a-roof-assembly","iwuic-2021-class-1-2-multilayered-glazing","iwuic-2021-class-1-2-noncombustible-deck","iwuic-2021-class-1-2-noncombustible-exterior-door","iwuic-2021-class-1-2-noncombustible-exterior-wall","iwuic-2021-class-1-2-quarter-inch-vent-mesh","iwuic-2021-class-1-2-solid-core-exterior-door","iwuic-2021-class-1-noncombustible-eave","iwuic-2021-class-2-solid-eave-enclosure","iwuic-2021-class-3-class-b-roof-assembly","iwuic-2021-noncombustible-gutters","iwuic-2021-roof-profile-closure","iwuic-2021-roof-valley-flashing"],"requirementCoverage":"partial","requirementCoverageSummary":"Fourteen source-exact 2021 IWUIC product-semantic atoms are normalized from the reviewed Class 1, Class 2, and Class 3 Chapter 5 provisions. This is not full-code normalization; ignition-resistant, fire-retardant-treated-wood, heavy-timber, rated-construction, cap-sheet, debris-control, and approval paths without complete product-field semantics remain outside the set. No 2018 or 2024 requirement is carried in by resemblance.","requirementScopes":[{"requirementId":"iwuic-2021-class-1-2-20-minute-exterior-door","scopeKeys":["ignition-resistant-class-1","ignition-resistant-class-2"],"scopeSummary":"This rated-door path applies only after official review assigns Class 1 or Class 2 construction.","sourceSections":["504.9","505.9"]},{"requirementId":"iwuic-2021-class-1-2-class-a-roof-assembly","scopeKeys":["ignition-resistant-class-1","ignition-resistant-class-2"],"scopeSummary":"This Class A roof path applies only after official review assigns Class 1 or Class 2 construction.","sourceSections":["504.2","505.2"]},{"requirementId":"iwuic-2021-class-1-2-multilayered-glazing","scopeKeys":["ignition-resistant-class-1","ignition-resistant-class-2"],"scopeSummary":"This glazing path applies only after official review assigns Class 1 or Class 2 construction.","sourceSections":["504.8","505.8"]},{"requirementId":"iwuic-2021-class-1-2-noncombustible-deck","scopeKeys":["ignition-resistant-class-1","ignition-resistant-class-2"],"scopeSummary":"This appendage path applies only after official review assigns Class 1 or Class 2 construction.","sourceSections":["504.7","505.7"]},{"requirementId":"iwuic-2021-class-1-2-noncombustible-exterior-door","scopeKeys":["ignition-resistant-class-1","ignition-resistant-class-2"],"scopeSummary":"This door-material path applies only after official review assigns Class 1 or Class 2 construction.","sourceSections":["504.9","505.9"]},{"requirementId":"iwuic-2021-class-1-2-noncombustible-exterior-wall","scopeKeys":["ignition-resistant-class-1","ignition-resistant-class-2"],"scopeSummary":"This wall-material path applies only after official review assigns Class 1 or Class 2 construction.","sourceSections":["504.5","505.5"]},{"requirementId":"iwuic-2021-class-1-2-quarter-inch-vent-mesh","scopeKeys":["ignition-resistant-class-1","ignition-resistant-class-2"],"scopeSummary":"This prescriptive vent path applies only after official review assigns Class 1 or Class 2 construction.","sourceSections":["504.10","505.10"]},{"requirementId":"iwuic-2021-class-1-2-solid-core-exterior-door","scopeKeys":["ignition-resistant-class-1","ignition-resistant-class-2"],"scopeSummary":"This door-leaf path applies only after official review assigns Class 1 or Class 2 construction.","sourceSections":["504.9","505.9"]},{"requirementId":"iwuic-2021-class-1-noncombustible-eave","scopeKeys":["ignition-resistant-class-1"],"scopeSummary":"This eave-material path applies only after official review assigns Class 1 construction.","sourceSections":["503.2","504.3"]},{"requirementId":"iwuic-2021-class-2-solid-eave-enclosure","scopeKeys":["ignition-resistant-class-2"],"scopeSummary":"This solid-enclosure path applies only after official review assigns Class 2 construction.","sourceSections":["505.3"]},{"requirementId":"iwuic-2021-class-3-class-b-roof-assembly","scopeKeys":["ignition-resistant-class-3"],"scopeSummary":"This Class B-or-better roof path applies only after official review assigns Class 3 construction.","sourceSections":["506.2"]},{"requirementId":"iwuic-2021-noncombustible-gutters","scopeKeys":["ignition-resistant-class-1","ignition-resistant-class-2","ignition-resistant-class-3"],"scopeSummary":"This gutter-material path applies after official review assigns Class 1, Class 2, or Class 3 construction.","sourceSections":["504.4","505.4","506.4"]},{"requirementId":"iwuic-2021-roof-profile-closure","scopeKeys":["ignition-resistant-class-1","ignition-resistant-class-2","ignition-resistant-class-3"],"scopeSummary":"This roof-profile path applies after official review assigns Class 1, Class 2, or Class 3 construction.","sourceSections":["504.2","505.2","506.2"]},{"requirementId":"iwuic-2021-roof-valley-flashing","scopeKeys":["ignition-resistant-class-1","ignition-resistant-class-2","ignition-resistant-class-3"],"scopeSummary":"This valley-flashing path applies after official review assigns Class 1, Class 2, or Class 3 construction.","sourceSections":["504.2.1","505.2.1","506.2.1"]}],"requirementCrosswalk":[{"modelRequirementId":"iwuic-2021-class-1-2-20-minute-exterior-door","disposition":"adopted-unchanged","replacementRequirementIds":[],"scopeSummary":"The State final report records the 2021 IWUIC as adopted without modification.","sourceSections":["504.9","505.9"]},{"modelRequirementId":"iwuic-2021-class-1-2-class-a-roof-assembly","disposition":"adopted-unchanged","replacementRequirementIds":[],"scopeSummary":"The State final report records the 2021 IWUIC as adopted without modification.","sourceSections":["504.2","505.2"]},{"modelRequirementId":"iwuic-2021-class-1-2-multilayered-glazing","disposition":"adopted-unchanged","replacementRequirementIds":[],"scopeSummary":"The State final report records the 2021 IWUIC as adopted without modification.","sourceSections":["504.8","505.8"]},{"modelRequirementId":"iwuic-2021-class-1-2-noncombustible-deck","disposition":"adopted-unchanged","replacementRequirementIds":[],"scopeSummary":"The State final report records the 2021 IWUIC as adopted without modification.","sourceSections":["504.7","505.7"]},{"modelRequirementId":"iwuic-2021-class-1-2-noncombustible-exterior-door","disposition":"adopted-unchanged","replacementRequirementIds":[],"scopeSummary":"The State final report records the 2021 IWUIC as adopted without modification.","sourceSections":["504.9","505.9"]},{"modelRequirementId":"iwuic-2021-class-1-2-noncombustible-exterior-wall","disposition":"adopted-unchanged","replacementRequirementIds":[],"scopeSummary":"The State final report records the 2021 IWUIC as adopted without modification.","sourceSections":["504.5","505.5"]},{"modelRequirementId":"iwuic-2021-class-1-2-quarter-inch-vent-mesh","disposition":"adopted-unchanged","replacementRequirementIds":[],"scopeSummary":"The State final report records the 2021 IWUIC as adopted without modification.","sourceSections":["504.10","505.10"]},{"modelRequirementId":"iwuic-2021-class-1-2-solid-core-exterior-door","disposition":"adopted-unchanged","replacementRequirementIds":[],"scopeSummary":"The State final report records the 2021 IWUIC as adopted without modification.","sourceSections":["504.9","505.9"]},{"modelRequirementId":"iwuic-2021-class-1-noncombustible-eave","disposition":"adopted-unchanged","replacementRequirementIds":[],"scopeSummary":"The State final report records the 2021 IWUIC as adopted without modification.","sourceSections":["503.2","504.3"]},{"modelRequirementId":"iwuic-2021-class-2-solid-eave-enclosure","disposition":"adopted-unchanged","replacementRequirementIds":[],"scopeSummary":"The State final report records the 2021 IWUIC as adopted without modification.","sourceSections":["505.3"]},{"modelRequirementId":"iwuic-2021-class-3-class-b-roof-assembly","disposition":"adopted-unchanged","replacementRequirementIds":[],"scopeSummary":"The State final report records the 2021 IWUIC as adopted without modification.","sourceSections":["506.2"]},{"modelRequirementId":"iwuic-2021-noncombustible-gutters","disposition":"adopted-unchanged","replacementRequirementIds":[],"scopeSummary":"The State final report records the 2021 IWUIC as adopted without modification.","sourceSections":["504.4","505.4","506.4"]},{"modelRequirementId":"iwuic-2021-roof-profile-closure","disposition":"adopted-unchanged","replacementRequirementIds":[],"scopeSummary":"The State final report records the 2021 IWUIC as adopted without modification.","sourceSections":["504.2","505.2","506.2"]},{"modelRequirementId":"iwuic-2021-roof-valley-flashing","disposition":"adopted-unchanged","replacementRequirementIds":[],"scopeSummary":"The State final report records the 2021 IWUIC as adopted without modification.","sourceSections":["504.2.1","505.2.1","506.2.1"]}],"supportingSources":[{"title":"2021 ICC Code Adoption Final Report","url":"https://www.pa.gov/content/dam/copapwp-pagov/en/dli/documents/ucc/documents/2021%20icc%20code%20adoption%20final%20report.pdf","publisher":"Pennsylvania Department of Labor & Industry","sourceType":"official","accessedOn":"2026-08-27T00:00:00.000Z"},{"title":"2021 International Wildland-Urban Interface Code, Chapter 5","url":"https://codes.iccsafe.org/content/IWUIC2021P2/chapter-5-special-building-construction-regulations","publisher":"International Code Council","sourceType":"official","accessedOn":"2026-08-27T00:00:00.000Z"}],"unresolvedPredicates":["official-hazard-map","official-hazard-class","project-type","official-confirmation"],"source":{"title":"34 Pa. Code § 403.21 Uniform Construction Code","url":"https://www.pacodeandbulletin.gov/secure/pacode/data/034/chapter403/s403.21.html","publisher":"Pennsylvania Code and Bulletin","sourceType":"official","accessedOn":"2026-08-27T00:00:00.000Z"},"author":"grayson-graham","reviewStatus":"draft","lastVerified":"2026-08-27T00:00:00.000Z"}],"products":[{"id":"polyglass-usa-inc-elastoflex-sa-p-fr-polyflex-sa-p-fr-elastobase-v","name":"Elastoflex SA P FR, Polyflex SA P FR, Elastobase V, Elastoflex SA V FR","url":"/materials/polyglass-usa-inc-elastoflex-sa-p-fr-polyflex-sa-p-fr-elastobase-v/","categories":["roofing"],"complianceStatus":"listed","documentedAttributes":[{"attribute":"assemblyRole","value":"roof-assembly","source":{"title":"CAL FIRE OSFM listing 8180-2305:0505","url":"https://calfire.govmotus.org/GOVFirePublicReport/ReportPublic?AppNum=CF24019388BML&type=BMLLINGLISTNEW","publisher":"CAL FIRE OSFM","accessedOn":"2026-08-26T00:00:00.000Z","sourceType":"official-listing"},"documentLocation":"Listing 8180-2305:0505, Design field","excerpt":"Elastoflex SA P FR, Polyflex SA P FR, Elastobase V, Elastoflex SA V FR, and Elastoflex SA V Plus FR are modified bitumen products that can be layered to form a Class A Roofing Systems."},{"attribute":"fireRating","value":"class-a","source":{"title":"CAL FIRE OSFM listing 8180-2305:0505","url":"https://calfire.govmotus.org/GOVFirePublicReport/ReportPublic?AppNum=CF24019388BML&type=BMLLINGLISTNEW","publisher":"CAL FIRE OSFM","accessedOn":"2026-08-26T00:00:00.000Z","sourceType":"official-listing"},"documentLocation":"Listing 8180-2305:0505, Design field","excerpt":"Approved Class A system."},{"attribute":"testStandard","value":"ul-790","source":{"title":"CAL FIRE OSFM listing 8180-2305:0505","url":"https://calfire.govmotus.org/GOVFirePublicReport/ReportPublic?AppNum=CF24019388BML&type=BMLLINGLISTNEW","publisher":"CAL FIRE OSFM","accessedOn":"2026-08-26T00:00:00.000Z","sourceType":"official-listing"},"documentLocation":"Listing 8180-2305:0505, Approval field","excerpt":"Complies with the applicable requirements in UL 790, 8th Edition."}]},{"id":"owens-corning-titanium-fr-aluminum-panel-assembly","name":"Owens Corning Titanium FR 0.032-inch aluminum-panel roof assembly","url":"/materials/owens-corning-titanium-fr-aluminum-panel-assembly/","categories":["roofing"],"complianceStatus":"attribute-match","documentedAttributes":[{"attribute":"assemblyRole","value":"roof-assembly","source":{"title":"Titanium FR installation instructions","url":"https://www.owenscorning.com/en-us/roofing/install-instructions/titanium-fr","publisher":"Owens Corning Roofing and Asphalt, LLC","accessedOn":"2026-08-24T00:00:00.000Z","sourceType":"manufacturer"},"documentLocation":null,"excerpt":null},{"attribute":"fireRating","value":"class-a","source":{"title":"Titanium FR installation 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instructions","url":"https://www.owenscorning.com/en-us/roofing/install-instructions/titanium-fr","publisher":"Owens Corning Roofing and Asphalt, LLC","accessedOn":"2026-08-24T00:00:00.000Z","sourceType":"manufacturer"},"documentLocation":null,"excerpt":null},{"attribute":"fireRating","value":"class-a","source":{"title":"Titanium FR installation instructions","url":"https://www.owenscorning.com/en-us/roofing/install-instructions/titanium-fr","publisher":"Owens Corning Roofing and Asphalt, LLC","accessedOn":"2026-08-24T00:00:00.000Z","sourceType":"manufacturer"},"documentLocation":null,"excerpt":null},{"attribute":"testStandard","value":"astm-e108","source":{"title":"Titanium FR installation instructions","url":"https://www.owenscorning.com/en-us/roofing/install-instructions/titanium-fr","publisher":"Owens Corning Roofing and Asphalt, 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LLC","accessedOn":"2026-08-24T00:00:00.000Z","sourceType":"manufacturer"},"documentLocation":null,"excerpt":null},{"attribute":"testStandard","value":"astm-e108","source":{"title":"Titanium FR installation instructions","url":"https://www.owenscorning.com/en-us/roofing/install-instructions/titanium-fr","publisher":"Owens Corning Roofing and Asphalt, LLC","accessedOn":"2026-08-24T00:00:00.000Z","sourceType":"manufacturer"},"documentLocation":null,"excerpt":null}]},{"id":"owens-corning-titanium-fr-tile-assembly","name":"Owens Corning Titanium FR concrete-or-clay-tile roof assembly","url":"/materials/owens-corning-titanium-fr-tile-assembly/","categories":["roofing"],"complianceStatus":"attribute-match","documentedAttributes":[{"attribute":"assemblyRole","value":"roof-assembly","source":{"title":"Titanium FR installation instructions","url":"https://www.owenscorning.com/en-us/roofing/install-instructions/titanium-fr","publisher":"Owens Corning Roofing and Asphalt, LLC","accessedOn":"2026-08-24T00:00:00.000Z","sourceType":"manufacturer"},"documentLocation":null,"excerpt":null},{"attribute":"fireRating","value":"class-a","source":{"title":"Titanium FR installation instructions","url":"https://www.owenscorning.com/en-us/roofing/install-instructions/titanium-fr","publisher":"Owens Corning Roofing and Asphalt, LLC","accessedOn":"2026-08-24T00:00:00.000Z","sourceType":"manufacturer"},"documentLocation":null,"excerpt":null},{"attribute":"testStandard","value":"astm-e108","source":{"title":"Titanium FR installation instructions","url":"https://www.owenscorning.com/en-us/roofing/install-instructions/titanium-fr","publisher":"Owens Corning Roofing and Asphalt, 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."}