Glossary

Light gauge steel, defined.

Plain-English definitions of the light gauge steel (LGS) and cold-formed steel (CFS) terms used across our work and these guides.

Light gauge steel (LGS): Structural framing made from thin sheets of galvanized steel cold-formed into shapes such as studs, tracks, and joists. Used as the structural skeleton of a building in place of dimensional lumber. Also called cold-formed steel (CFS) or, generically, steel framing.
Cold-formed steel (CFS): The formal engineering name for light gauge steel: steel shaped at room temperature (cold) by roll-forming or pressing, rather than by heating. LGS, CFS, and cold-formed steel framing all refer to the same material; CFS is the term used in the AISI S240 and S100 framing standards.
Steel framing: A general term for a building's structural frame built from steel. In residential, ADU, and mid-rise construction it most often means light gauge (cold-formed) steel framing, as distinct from heavy hot-rolled structural steel. People searching for steel framing, cold-formed steel framing, or light gauge steel framing are describing the same system.
Roll-forming: The manufacturing process that shapes thin sheet steel into structural profiles by passing it through a series of rollers at room temperature.
Slitting: Cutting a wide master coil of steel lengthwise into narrower strips of the exact widths required to roll-form a given profile.
Master coil: A large coil of sheet steel that serves as the raw input to a steel fabrication line, before slitting and roll-forming.
Galvanized steel: Steel coated with zinc to resist corrosion. Light gauge steel framing is typically galvanized for durability.
Stud: A vertical framing member in a wall. In light gauge steel, studs are roll-formed C-shaped sections.
Track: The horizontal member at the top and bottom of a light gauge steel wall that the studs seat into.
Joist: A horizontal framing member that supports a floor or roof. Light gauge steel joists span between walls or beams.
Panelized construction: A method in which wall, floor, and roof panels are fabricated in a factory, shipped flat, and assembled (erected) on site. The process of building in panels is also called panelization.
Volumetric modular: A method in which complete three-dimensional building modules are built in a factory, often with finishes and systems installed, then transported and set on the foundation.
Module: A complete three-dimensional section of a building, such as a room or group of rooms, fabricated in a factory for volumetric modular construction.
Podium (Type III) construction: A mid-rise approach that places several storeys of residential framing over a concrete podium containing parking or retail. Common for mid-rise multifamily.
Wet-room pod: A factory-built bathroom or kitchen module, complete with plumbing and fixtures, that is installed into a building as a finished unit.
Prefabrication: Building components or assemblies in a factory before delivery to the jobsite, rather than building everything in place on site.
Non-combustible: A material that does not ignite, burn, or contribute fuel to a fire. Steel is non-combustible.
Chapter 7A: The section of the California Building Code that sets materials and assembly requirements for buildings in wildland-urban interface (WUI) fire areas, covering cladding, vents, decking, and more.
Seismic retrofit: Strengthening an existing building to better resist earthquakes, for example soft-story retrofits of multifamily buildings in California.
Structural steel: Heavy hot-rolled steel members such as beams and columns, distinct from light gauge (cold-formed) steel. The two are often used together in a building.
ADU: Accessory dwelling unit: a secondary home on a residential lot, such as a backyard unit or garage conversion. ADUs can be single-family or part of a multifamily property.

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Light Gauge Steel: the overview All insights