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Home / Assemblies / UL U161
UL U1613-hr Fire RatingWallLoad-BearingSTC 50
Wood StudMulti-Layer GypsumMineral WoolLoad-Bearing WallDesign

Wood Stud Wall — 2 layers 1/2" Type X

UL-listed 3-hour fire-rated wood stud wall assembly. 2x6 wood studs at 16" o.c. with R-21 mineral wool batt, 2 layers of 1/2" Type X gypsum board each side.

Cross-Section Diagram

1234569.00"WALL ASSEMBLYSECTION · NOT TO SCALE6 LAYERSsee legend for ① ② ③
Legend
11/2" Type X gypsum board(1/2")
21/2" Type X gypsum board(1/2")
32x6 wood studs at 16" o.c.(5.5")
4R-21 mineral wool batt
51/2" Type X gypsum board(1/2")
61/2" Type X gypsum board(1/2")

Specifications

Fire Rating
3-Hour
STC Rating
STC 50
Load Bearing
Yes
Total Thickness
7.5"
Source / Publisher
UL (Underwriters Laboratories)
Design Number
U161
Assembly Type
Wall
Test Standard
ASTM E119
Construction Group
Light Frame
Number of Layers
6 layers

Applicable Codes

IRC R302.1IBC 2024 Table 722.1IBC 2024 §722

Construction Summary

2x6 wood studs at 16" o.c. with R-21 mineral wool batt, 2 layers of 1/2" Type X gypsum board each side

Material Layers

LayerMaterialThickness
11/2" Type X gypsum board1/2"
21/2" Type X gypsum board1/2"
32x6 wood studs at 16" o.c.5.5"
4R-21 mineral wool batt—
51/2" Type X gypsum board1/2"
61/2" Type X gypsum board1/2"

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.