Fire and Shaft Walls speaks to types of fire and shaft walls, what are fire and shaft walls and why fire and shaft walls for requirements and considerations in building construction.
A fire wall is a wall that forms a required separation to restrict the spread of fire through a building and extends continuously from the foundation to or through the roof. A fire wall is used to divide a single building into smaller units, each of which may be considered as a separate building when calculating allowable heights and areas under the building code.
A fire wall must either meet a non combustible roof structure at the top or extend through and above the roof by a specified minimum distance, 30 inches (762 mm) in the case of the International Building Code (IBC). In this code, a fire wall must also extend horizontally at least 18 inches (457 mm) beyond the exterior walls of the building unless these exterior walls meet certain fire resistance and combustibility requirements.
Except of buildings of Type V construction, a fire wall must be framed with non combustible materials such as steel studs. A fire wall must also have sufficient structural stability during a building fire to allow collapse of the construction on either side without itself collapsing.
Openings in fire walls are restricted in size and aggregate area and must be closed with fire doors or fire rated glass. The required resistance ratings for fire walls are given under The International Building Code.
A shaft wall is used to enclose a multi story opening through a building, such as an elevator shaft or a shaft for ductwork, conduits or pipes. In the International Building Code, a shaft wall connecting four or more floors, must have a rating of 2 hours or, if connecting fewer floors, a rating of 1 hour.
Walls for elevator shafts must be able to withstand the air pressure and suction loads placed on them by the movements of the elevator cars within the shaft, and should be designed to prevent the noise of the elevator machinery from reaching other areas of the building.