USG Cavity Wall Shaft Systems Page 9

USG Cavity Shaft Wall Systems

Elevator Door Frame Assemblies
Typically, for buildings of four stories or more, building codes require a 1-1/2-hour "B" rating for elevator entranceways in a 2-hour rated shaft wall. Certain firms have conducted fire tests with their door and frame assemblies in USG Cavity Shaft Walls—UL Design U438 rated 2 hours. These door assemblies comply with the safety code for elevators and dumbwaiters ANSI A17.1 and have been tested per ASTM E152. Specific door jamb studs, jamb struts and installation methods are required for fire-rated construction. See entrance manufacturer for details. When specifying door frame assemblies, also specify installation in the shaft wall in which assemblies were performance-tested.

There have been many successful UL tests on door assemblies in USG Cavity Shaft Walls. In every successful test, the interface between the entranceway and shaft wall was constructed with a 20 ga. jamb strut having a 3 in. leg, installed at the door jamb.

Both the 20 ga. thickness and the 3 in. leg length in the jamb strut are required to achieve tested performance.

Shaft Wall Entranceway Assemblies–    1-1/2 hr. Fire Rated

Note: Entranceways tested with UL Design U438 shaft wall and achieved a 11/2-hour "B’’ rating.
Apparent duplications are a result of tests involving different types or styles of either frames or doors.