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Home / Assemblies / UL C118
UL C1183-hr Fire RatingJoint System
Mineral WoolDesign

Wall-to-Wall Joint — Intumescent System

UL-listed 3-hour fire-rated wall-to-wall joint system. Wall-to-Wall Joint, 2" max width, Intumescent wrap strip with mineral wool backer.

Cross-Section Diagram

12FIRE-RATED JOINTSECTION · NOT TO SCALE2 LAYERSsee legend for ① ② ③
Legend
1Mineral wool backer(2")
2Intumescent wrap strip(5/8")

Specifications

Fire Rating
3-Hour
Load Bearing
No
Total Thickness
Varies
Source / Publisher
UL (Underwriters Laboratories)
Design Number
C118
Assembly Type
Joint System
Test Standard
ASTM E1966
Construction Group
N/A
Number of Layers
2 layers

Applicable Codes

NFPA 5000IBC 2024 §714

Construction Summary

Wall-to-Wall Joint, 2" max width, Intumescent wrap strip with mineral wool backer

Material Layers

LayerMaterialThickness
1Mineral wool backer2"
2Intumescent wrap strip5/8"

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.