USG Cavity Wall Shaft Systems Page 2

USG Cavity Shaft Wall Systems

Fire-Resistant Drywall Partitions for Enclosing Shafts in Multi-Story Buildings
2-hour assemblies

Description
USG Cavity Shaft Walls offer high performance characteristics and greater economy than other shaft walls. Engineered design of the C-H Stud system provides a thin, lightweight assembly that offers fast installation and low material costs, producing low in-place costs as well as savings in structural steel. In addition, USG Shaft Walls provide up to 4-hour fire resistance and sound ratings to 51 STC. They resist intermittent lateral loads up to 15 psf; also resist fatigue failure under cyclic lateral loading.

USG Cavity Shaft Walls are non-load-bearing gypsum board partition assemblies designed for erection from outside the shaft at each floor. Shafts are enclosed early in construction, the walls finished later along with interior partitions. This fast-installation feature combined with low-cost materials and high performance values makes USG Cavity Shaft Walls superior enclosures for elevator and mechanical shafts, air ducts and stairwells in multistory buildings.

USG Cavity Shaft Walls are covered by three model building codes under NER 258. In addition to a 1 -1 /2" deep x 22-1/2" wide vertical chaseway, the C-H Stud used has 1 " dia. holes 16" from each end for horizontal conduit runs. A 3" deep chase to carry electrical elevator controls is available with the 4" C-H Stud and a 5" chase for 6" studs.

The assemblies are simply constructed of SHEETROCK brand Gypsum Panels, FIRECODE C Core, or IMPERIAL FIRECODE C Gypsum Base and veneer finish, steel studs and runners, and SHEETROCK brand Gypsum Liner Panels.

SHEETROCK brand Gypsum Liner Panels are installed vertically between USG Steel J-Runners attached to floor and ceiling. Panel edges are inserted into specially formed USG Steel C-H Studs spaced 24" o.c. The 2-hour shaft wall is completed with double-layer 1/2" thick gypsum panels and a United States Gypsum Company joint system, or with gypsum base and veneer finish applied to one side. Where both sides of the wall must be finished, single-layer panels are applied to each side of studs, A 1-hour assembly is obtained with single-layer 5/8" thick face panels. Additional layers of panels are installed in 3- and 4-hour fire-rated construction.

Liner panels have a special fire-resistant core and multi-layered green paper facings that are treated to resist moisture penetration. The panels are 1 " thick, 24" wide and have beveled edges. SHEETROCK brand Gypsum Panels, FIRECODE C Core, for these systems are 1/2" or 5/8" thick and 41 wide. IMPERIAL FIRECODE C Gypsum Base, 1/2" or 5/8" thick and 4' wide, has a high-strength, high-density core covered with special -absorption face paper for a veneer finish. USG Steel J-Runners, C-H Studs and E-Studs are formed from hot-dipped galvanized steel.