What is Mechanical Shaft?
Definition of Mechanical Shaft in Construction
In most commercial, industrial or multi- family buildings, there is a need for mechanical shafts to run vertically and in some cases, horizontally, within the structure.
These mechanical shafts offer the ability to route various utilities through the structure. If there are roof top units on the building, shafts must lead the air distribution from the roof, down into the structure. If there are return air ducts, these return air ducts must be routed through the structure in the vertical and horizontal directions. The design of mechanical shafts is architecturally important due to their space requirements, as well as the need to locate these shafts in critical areas of the structure.
The mechanical shafts require detailed fireproofing and in many instances 2 hour rated walls and fire dampers are required within the shafts, or in all ductwork exiting the shafts. The fireproofing requirements of mechanical shafts is extremely important in the design of all structures. The chimney affect of an open shaft or a improperly designed shaft can have a devastating affect, if a fire were to break out. Mechanical shafts are normally constructed of concrete, masonry or a two hour gypsum assembly called shaft wall. Shaft wall is used in certain instances when the installation of masonry is either not possible or there are space limitations. Shaft wall is a product that is designed to offer fire protection by the proper installation of thick gypsum board panels, supported with specially constructed metal studs.