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Home / Assemblies / UL U320
UL U3201.5-hr Fire RatingWallSTC 40
Steel StudGypsum BoardMineral WoolPartitionDesign

Shaft Wall — single layer 5/8" Type X

UL-listed 1.5-hour fire-rated shaft wall assembly. 2-1/2" CT studs at 24" o.c. with R-8 mineral wool, single layer of 5/8" Type X gypsum board each side.

Cross-Section Diagram

12345.25"WALL ASSEMBLYSECTION · NOT TO SCALE4 LAYERSsee legend for ① ② ③
Legend
15/8" Type X gypsum board(5/8")
22-1/2" CT studs at 24" o.c.(2.5")
3R-8 mineral wool
45/8" Type X gypsum board(5/8")

Specifications

Fire Rating
1.5-Hour
STC Rating
STC 40
Load Bearing
No
Total Thickness
3.75"
Source / Publisher
UL (Underwriters Laboratories)
Design Number
U320
Assembly Type
Wall
Test Standard
UL 263
Construction Group
Concrete/Masonry
Number of Layers
4 layers

Applicable Codes

NFPA 5000IBC 2024 §722IBC 2021 §722

Construction Summary

2-1/2" CT studs at 24" o.c. with R-8 mineral wool, single layer of 5/8" Type X gypsum board each side

Material Layers

LayerMaterialThickness
15/8" Type X gypsum board5/8"
22-1/2" CT studs at 24" o.c.2.5"
3R-8 mineral wool—
45/8" Type X gypsum board5/8"

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.