USG Cavity Wall Shaft Systems Page 10

USG Cavity Shaft Wall Systems

Horizontal Shaft-Wall Assemblies
USG Cavity Shaft Walls installed horizontally provide economical construction for fire-resistive duct protection, corridor and other ceilings and stairway soffits. Also ideal for ceilings over office areas in pitched-roof buildings and in modular buildings where ceiling framing is independent of the floor above. With 1" liner panels inserted in C-H Studs 24" o.c. and triple-layer 1/2" SHEETROCK brand Gypsum Panels, FIRECODE C Core, screw-attached to studs, the system provides greater spans and 2 hr. protection from fire either inside or outside the duct. Test No.: WHI-495 PSH 0154/0167.

With double-layer 1/2" SHEETROCK brand Gypsum Panels, FIRECODE C Core, screw-attached to studs, the assembly provides suitable 2-hour fire-resistive ceiling construction for corridors and stairs (see details).

One-hour fire-rated construction is offered with single-layer 5/8" SHEETROCK brand Gypsum Panels, FIRECODE C Core.

Limitations

1. USG C-H Studs are not designed to carry live loads or mechanical equipment or provide material storage area.
2. Maximum stud spacing is 24" o.c.; maximum spans are shown in table below.

Limiting Spans--Horizontal Shaft Walls ⁽¹⁾

(1) Based on U240 allowable deflection and JR24 runner.
(2) Allowable steel stress reduced 50%,
(3) Full steel stress allowed based on ASTM E119.