UL D1541.5-hr Fire RatingFloor/CeilingLoad-BearingSTC 48
Steel JoistGypsum BoardFiberglass BattDesign
Steel Joist Floor/Ceiling — 2 layers 5/8" Type X gypsum board
UL-listed 1.5-hour fire-rated steel joist floor/ceiling assembly. Open-web steel joists at 48" o.c. with R-19 fiberglass batt, 2 layers of 5/8" Type X 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 48" o.c.(14.0")
4R-19 fiberglass batt
55/8" Type X gypsum board(5/8")
65/8" Type X gypsum board(5/8")
Specifications
Fire Rating
1.5-Hour
STC Rating
STC 48
Load Bearing
Yes
Total Thickness
16.75"
Applicable Codes
IBC 2021 §722IBC 2021 Table 722.1
Construction Summary
Open-web steel joists at 48" o.c. with R-19 fiberglass batt, 2 layers of 5/8" Type X 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.