{"id":"class-a","license":"CC-BY-4.0","data":{"term":"Class A","shortDef":"The most severe roof-assembly class under ASTM E108 or UL 790. Oregon R327’s floor is Class B. IBHS Essential asks for Class A.","relatedGlossary":["assembly"],"relatedCategories":["roofing"],"relatedStandards":["astm-e108-ul-790"],"relatedGuides":["r327-vs-cwuic","how-to-read-a-class-a-roof-listing"],"author":"grayson-graham","reviewStatus":"draft","lastVerified":"2026-08-23T00:00:00.000Z"}}