I often make the mistake of using metal building terminology assuming people know what I am talking about. While metal buildings are not complicated, without an understanding of the basic components, they can be confusing. Some of the terminology and labeling differs from more conventional construction methods. Below is a list of the major components as well as a description of labeling and dimensioning standards.
Components of the Building
Primary Framing: The main frames of the building system, consisting of columns and rafters. The primary framing members carry loads directly down to the foundations.
Secondary Framing: Members that attach to the primary framing system. The secondary framing members carry the loads on the surface of the building to the primary framing members. The most common members are roof purlins and wall girts. Bar-joists are utilized when roof loads exceed the capacity of roof purlins.
Eave Strut: The roof secondary member that sits at the intersection of the roof and wall.
Bracing: Combination of rods, cables, beams and/or frames that help transfer loads down to the foundation
Roof Covering: The metal panels on the surface of the roof, which attach to the roof secondary members. The roof covering can be a finished product exposed to the exterior; or it can be the substrate used to attach a conventional roof (rubber, shingle, etc.).
Wall Covering: The exterior metal panels on the surface of the walls, which attach directly to the wall secondary members. Other wall systems such as masonry, EIFS and Aluminum Composite Panel can be incorporated in lieu of a standard metal panel.
Labeling and Dimensioning
Sidewall: A wall that runs perpendicular to the building’s primary framing.
Endwall: An exterior wall that runs parallel with the primary framing.
Building Line: The exterior face of girt; also called Steel Line.
Length: The measurement along the sidewall of the building.
Width: The measurement along the endwall of the building.
Eave Height: The measurement from finished floor to top of eave strut.
Clear Height: The measurement from finished floor to lowest obstruction.
Bay Spacing: The distance between main frames. Interior bays are measured from the center line of the frames. End-bays are measured from the Building Line to the center line of frame.
This list is not all inclusive, but it provides a baseline understanding of the major building components and common terminology. In subsequent articles, we will dive deeper into the individual systems and components.