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Home / Assemblies / GA WP1218
GA WP12184-hr Fire RatingWallLoad-BearingSTC 42
Steel StudMulti-Layer GypsumLoad-Bearing WallDesign

GA Wood Stud Partition — 4 layers 5/8" Type C

Gypsum Association file WP1218 — 4-hour fire-rated wood stud partition. GA file WP1218: 3-5/8" steel studs at 24" o.c., 4 layers of 5/8" Type C gypsum board each side.

Cross-Section Diagram

1234567896.50"WALL ASSEMBLYSECTION · NOT TO SCALE9 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")
53-5/8" steel studs at 24" o.c.
65/8" Type C gypsum board(5/8")
75/8" Type C gypsum board(5/8")
85/8" Type C gypsum board(5/8")
95/8" Type C gypsum board(5/8")

Specifications

Fire Rating
4-Hour
STC Rating
STC 42
Load Bearing
Yes
Total Thickness
6.35"
Source / Publisher
GA (Gypsum Association)
Design Number
WP1218
Assembly Type
Wall
Test Standard
ASTM E119
Construction Group
Light Frame
Number of Layers
9 layers

Applicable Codes

IRC R302.1IBC 2021 Table 722.1

Construction Summary

GA file WP1218: 3-5/8" steel studs at 24" o.c., 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"
53-5/8" steel studs at 24" o.c.—
65/8" Type C gypsum board5/8"
75/8" Type C gypsum board5/8"
85/8" Type C gypsum board5/8"
95/8" Type C gypsum board5/8"

Important Notice

This assembly listing is for reference only. Always verify against the current GA Fire Resistance Design Manual database before specifying in construction documents. Material substitutions may void the fire rating. Consult with a qualified fire protection engineer for project-specific requirements.