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Home / Assemblies / UL U123
UL U1234-hr Fire RatingWallLoad-BearingSTC 52
Wood StudMulti-Layer GypsumMineral WoolLoad-Bearing WallDesign

Wood Stud Wall — 4 layers 5/8" Type C

UL-listed 4-hour fire-rated wood stud wall assembly. 2x4 wood studs at 16" o.c. with R-15 mineral wool batt, 4 layers of 5/8" Type C gypsum board each side.

Cross-Section Diagram

1234567891010.00"WALL ASSEMBLYSECTION · NOT TO SCALE10 LAYERSsee legend for ① ② ③
Legend
15/8" Type C gypsum board(5/8")
25/8" Type C gypsum board(5/8")
35/8" Type C gypsum board(5/8")
45/8" Type C gypsum board(5/8")
52x4 wood studs at 16" o.c.(3.5")
6R-15 mineral wool batt
75/8" Type C gypsum board(5/8")
85/8" Type C gypsum board(5/8")
95/8" Type C gypsum board(5/8")
105/8" Type C gypsum board(5/8")

Specifications

Fire Rating
4-Hour
STC Rating
STC 52
Load Bearing
Yes
Total Thickness
8.5"
Source / Publisher
UL (Underwriters Laboratories)
Design Number
U123
Assembly Type
Wall
Test Standard
UL 263
Construction Group
Light Frame
Number of Layers
10 layers

Applicable Codes

NFPA 5000IBC 2021 Table 722.1IBC 2021 §722

Construction Summary

2x4 wood studs at 16" o.c. with R-15 mineral wool batt, 4 layers of 5/8" Type C gypsum board each side

Material Layers

LayerMaterialThickness
15/8" Type C gypsum board5/8"
25/8" Type C gypsum board5/8"
35/8" Type C gypsum board5/8"
45/8" Type C gypsum board5/8"
52x4 wood studs at 16" o.c.3.5"
6R-15 mineral wool batt—
75/8" Type C gypsum board5/8"
85/8" Type C gypsum board5/8"
95/8" Type C gypsum board5/8"
105/8" Type C 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.