Steel Frame

Thin sheets of galvanized steel can be formed into steel studs used as a building material for rough-framing in commercial or residential construction (pictured), and many other applications. The dimension of the room is established with horizontal track that is anchored to the floor and ceiling to outline each room. The vertical studs are arranged in the tracks, usually spaced 16" apart, and fastened at the top and bottom.

Rectangular steel frame, or "perimeter frame" of the Willis building (at right) contrasted against the diagrid frame at 30 St Mary Axe, London, UK.

The primary shapes used in residential construction are the C-shape stud and the U-shaped track, and a variety of other shapes. Framing members are generally produced in a thickness of 12 to 25 gauge. The wall finish is anchored to the two flange sides of the stud, which varies from 1-1/4" to 3" thick, and the width of web ranges from 1-5/8" to 14". Rectangular sections are removed from the web to provide access for electrical wiring.
Steel mills produce galvanized sheet steel, the base material for light-gauge steel. Sheet steel is then roll-formed into the final profiles used for framing. The sheets are zinc coated (galvanized) to prevent oxidation and corrosion. Steel framing provides excellent design flexibility due to the inherent strength of steel, which allows it to span over a longer distance than wood, and also resist wind and earthquake loads.
Light Steel Framing has been extensively used in cold climate countries due to its good thermal and structural behaviour. Heat loss reduction and tenement thermal comfort have been the main driving forces defining the design of these frames. The main issue to be addressed is how striving for thermal efficiency can lead to structural weakening and poor fire performance.