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Home / Assemblies / GA FC4203
GA FC42031.5-hr Fire RatingFloor/CeilingLoad-BearingSTC 51
Wood JoistDesign

GA Floor/Ceiling with Gypsum Board — 1.5-hr

Gypsum Association file FC4203 — 1.5-hour fire-rated floor-ceiling assembly.

Cross-Section Diagram

1234FLOOR/CEILING ASSEMBLYSECTION · NOT TO SCALE4 LAYERSsee legend for ① ② ③
Legend
1Floor covering(varies)
23/4" OSB subfloor(3/4")
32x12 wood joists at 16" o.c.(9.25"-11.25")
45/8" Type X gypsum board(5/8")

Specifications

Fire Rating
1.5-Hour
STC Rating
STC 51
Load Bearing
Yes
Total Thickness
11.27"
Source / Publisher
GA (Gypsum Association)
Design Number
FC4203
Assembly Type
Floor/Ceiling
Test Standard
ASTM E119
Construction Group
Light Frame
Number of Layers
4 layers

Applicable Codes

IRC R302.1IBC 2024 §722

Construction Summary

GA file FC4203: Floor/Ceiling with Gypsum Board

Material Layers

LayerMaterialThickness
1Floor coveringvaries
23/4" OSB subfloor3/4"
32x12 wood joists at 16" o.c.9.25"-11.25"
45/8" Type X 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.