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Home / Assemblies / UL J103
UL J1032-hr Fire RatingJoint System
Mineral WoolDesign

Head-of-Wall Joint — Spray-applied System

UL-listed 2-hour fire-rated head-of-wall joint system. Head-of-Wall Joint, 1-1/2" max width, Spray-applied firestop material with mineral wool backer.

Cross-Section Diagram

12FIRE-RATED JOINTSECTION · NOT TO SCALE2 LAYERSsee legend for ① ② ③
Legend
1Mineral wool backer(3")
2Spray-applied firestop material(5/8")

Specifications

Fire Rating
2-Hour
Load Bearing
No
Total Thickness
Varies
Source / Publisher
UL (Underwriters Laboratories)
Design Number
J103
Assembly Type
Joint System
Test Standard
ASTM E1966
Construction Group
N/A
Number of Layers
2 layers

Applicable Codes

NFPA 5000IBC 2021 §715

Construction Summary

Head-of-Wall Joint, 1-1/2" max width, Spray-applied firestop material with mineral wool backer

Material Layers

LayerMaterialThickness
1Mineral wool backer3"
2Spray-applied firestop material5/8"

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.