UL D1194-hr Fire RatingFloor/CeilingLoad-BearingSTC 40
Steel JoistGypsum BoardFiberglass BattDesign
Steel Joist Floor/Ceiling — 3 layers 5/8" Type C gypsum board
UL-listed 4-hour fire-rated steel joist floor/ceiling assembly. Open-web steel joists at 24" o.c. with R-19 fiberglass batt, 3 layers of 5/8" Type C gypsum board ceiling.
Cross-Section Diagram
Legend
1Floor covering(varies)
22-1/2" lightweight concrete on steel deck(2-1/2")
3Open-web steel joists at 24" o.c.(14.0")
4R-19 fiberglass batt
55/8" Type C gypsum board(5/8")
65/8" Type C gypsum board(5/8")
75/8" Type C gypsum board(5/8")
Specifications
Fire Rating
4-Hour
STC Rating
STC 40
Load Bearing
Yes
Total Thickness
17.38"
Applicable Codes
NFPA 5000IBC 2024 §722
Construction Summary
Open-web steel joists at 24" o.c. with R-19 fiberglass batt, 3 layers of 5/8" Type C gypsum board ceiling
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.