
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
- USG C-H Studs are not designed to carry live loads or mechanical equipment or provide material storage area.
- Maximum stud spacing is 24" o.c.; maximum spans are shown in table below.
Limiting Spans--Horizontal Shaft Walls (1)
Stud Style |
Single-layer
5/8" gypsum panels(2) |
Double-layer
1/2" gypsum panels(2) |
Triple-layer
1/2" gypsum panels(3) |
212CH25 |
6'7" |
6'0" |
6'5" |
212CH22 |
9'4" |
8'6" |
7'11" |
212CH20 |
10'3" |
9'2" |
8'3" |
400CH25 |
8'8" |
7'10" |
8'6" |
400CH20 |
14'6" |
13'2" |
12'0" |
600CH20 |
17'5" |
15'10" |
13'8" |
(1) Based on U240 allowable deflection and JR24 runner.
(2) Allowable steel stress reduced 50%,
(3) Full steel stress allowed based on ASTM E119. |