Pre-engineered “rigid frame” steel buildings offer owners a number of benefits and advantages. In spite of the fact that they are relatively easy on the pocket, steel buildings are actually strong and durable because of their framing. Steel buildings are engineered to bolt together easily, making their construction fast, easy, and efficient. Assembling a steel building does not require any specialized skill in carpentry, masonry, and welding.

Main members that form the skeleton of the framework of steel buildings consist of vertical steel columns and horizontal I-beams. These columns and I-beams are constructed in a rectangular grid to support the floors, roof and walls that are attached to the skeleton frame. Basically, the skeleton holds things up.

Each frame is made up of two or more columns, supporting a rafter that traverses one side of the structure to the other. Spaced at equal intervals between the two endwalls, the main frames bear most of the building’s load. Each space between two frames of a steel building is called a “bay”, which ranges from 20 to 30 feet or 6 to 10 meters. Typically, the endwall frames support only half the load of a main frame.

Secondary framing includes the wall girts, roof purlins, and eave struts. In the middle of each main frame, there are girts and purlins which run up the roof and the wall horizontally after every 3 to 6 feet. Eave struts are structural members located at the eaves of steel buildings, which support the roof and wall paneling. These secondary framing members transfer loading to the main frames and help stabilize the steel building.