Metal Buildings – Bracing Systems

Metal buildings require bracing to resist the forces of wind, earthquakes, cranes & other load considerations. Each metal building manufacturer may have slightly different bracing offerings, but they they all essentially fall into three categories which are outline below.

Full Height X-Bracing

The standard system is full height X-bracing and it is the most economical bracing solution. X-bracing typically consists of threaded rod assemblies or in some situations high strength cables. High strength cables were more common in years past but they are seldom used today.

One key point about X-bracing is that it does not satisfy all requirements to temporarily brace a building during erection. A building must be temporarily braced until the roofing and siding is completed. The design and installation of the temporary bracing is the responsibility of the building erector, not the manufacturer.

Portal Frames

A portal frame is a rigid frame assembly rotated and placed between the primary frames. Portal frames are utilized when wall opening requirements prevent the utilization of X-bracing. For example, a distribution center may have dock doors located within every bay of the building which would prevent the use of X-bracing. Portal frames are also more costly than X-bracing.

Partial Height Portal Frames

A hybrid bracing system is a partial height portal frame. In a partial height portal frame the rigid frame is utilized to avoid an opening, and above the opening where there are no clearance requirements X-bracing is utilized.

Fixed Base Columns

If a condition arises where it is not feasible to utilize X-bracing or a portal frame, fixed base columns can be utilized. Fixed based columns are rarely utilized as they greatly increase the cost of the foundation system. When columns are made fixed, you are essentially creating a flag-pole and you are transferring the moment into the foundation. Because of this, fixed base columns are used as a last resort.