UL L1833-hr Fire RatingRoof/CeilingLoad-Bearing
Steel StudDesign
Steel Truss Roof/Ceiling — 3 layers Spray-applied fireproofing
UL-listed 3-hour fire-rated steel truss roof/ceiling assembly. Light gauge steel trusses at 24" o.c. with Rigid insulation board, 3 layers of Spray-applied fireproofing ceiling, 20 ga. steel deck.
Cross-Section Diagram
Legend
1Roof covering(varies)
220 ga. steel deck(varies)
3Light gauge steel trusses at 24" o.c.(12"-24")
4Rigid insulation board
5Spray-applied fireproofing(1-1/2")
6Spray-applied fireproofing(1-1/2")
7Spray-applied fireproofing(1-1/2")
Specifications
Fire Rating
3-Hour
Load Bearing
Yes
Total Thickness
18.5"
Applicable Codes
IRC R302.1IBC 2021 §722
Construction Summary
Light gauge steel trusses at 24" o.c. with Rigid insulation board, 3 layers of Spray-applied fireproofing ceiling, 20 ga. steel deck
Material Layers
Important Notice
This assembly listing is for reference only. Always verify against the current UL Product iQ database before specifying in construction documents. Material substitutions may void the fire rating. Consult with a qualified fire protection engineer for project-specific requirements.