B
HomeLibrariesCopilotSearchProjectsBookmarks
FeedbackHelp Desk
Libraries
Building Codes
Code LibraryIBC — BuildingIRC — ResidentialIFC — FireIPC — PlumbingIMC — MechanicalIFGC — Fuel GasIECC — EnergyNEC — ElectricalModel Codes
Specifications
CSI SpecificationsDOT SpecsTransit SpecsUSACE
Standards
TransportationRailroadFire SafetyAccessibilityStructural
Tools & References
DiagramsAssembliesProductsCalculatorsChecklistsPermits
PricingLog in
Home / Assemblies / UL U173
UL U1731-hr Fire RatingWallLoad-BearingSTC 49
Wood StudGypsum BoardMineral WoolLoad-Bearing WallDesign

Wood Stud Wall — single layer 1/2" Type X

UL-listed 1-hour fire-rated wood stud wall assembly. 2x6 wood studs at 24" o.c. with R-15 mineral wool batt, single layer of 1/2" Type X gypsum board each side.

Cross-Section Diagram

12348.00"WALL ASSEMBLYSECTION · NOT TO SCALE4 LAYERSsee legend for ① ② ③
Legend
11/2" Type X gypsum board(1/2")
22x6 wood studs at 24" o.c.(5.5")
3R-15 mineral wool batt
41/2" Type X gypsum board(1/2")

Specifications

Fire Rating
1-Hour
STC Rating
STC 49
Load Bearing
Yes
Total Thickness
6.5"
Source / Publisher
UL (Underwriters Laboratories)
Design Number
U173
Assembly Type
Wall
Test Standard
ASTM E119
Construction Group
Light Frame
Number of Layers
4 layers

Applicable Codes

IBC 2021 Table 722.1IBC 2024 §722IBC 2024 Table 722.1

Construction Summary

2x6 wood studs at 24" o.c. with R-15 mineral wool batt, single layer of 1/2" Type X gypsum board each side

Material Layers

LayerMaterialThickness
11/2" Type X gypsum board1/2"
22x6 wood studs at 24" o.c.5.5"
3R-15 mineral wool batt—
41/2" 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.