Cold-formed steel has been used in framing since approximately 1850. The Virginia Baptist Hospital, founded in 1924, was one of the earliest buildings to use cold-formed steel, not for the walls, but for the floors (it's still holding up well). Building standards for this technique were not codified until the 1930s and 40s, but once they were in place, cold-formed steel became very popular for building frames.
Cold-formed steel (CFS) has all the benefits of steel plus several advantages for contractors and labor.
What Exactly Is Cold-Formed Steel?
Cold-formed steel members are made from structural quality sheet steel formed into C-shaped sections and other shapes by rolling the steel through a series of dies without heating. The process is rather like forcing Play-Doh(R) through a forming tool that creates stars and other shapes.
Purlins, girts, zee’s, eave struts, angles, channels, hat sections and more are metal framing components created with cold-formed steel. It can be formed into multiple thicknesses for various structural and non-structural applications.
Comprehensive provisions for steel can be found in the International Building Codes, which adopted the American Iron and Steel Institute’s North American Standards for Cold-Formed Steel Framing. CFS has become increasingly popular for low to mid-rise frames over the decades.
What Are the Benefits of Cold-Formed Steel?
Cold-formed steel has numerous benefits for building construction and maintenance. Metal reacts predictably under different stressors and loads, enabling engineers to make precise determinations about various load factors and required thicknesses of steel.
- CFS has great strength and stiffness and does not crack, split, deform or shift from its location or dimensions. Steel’s strength allows designs with longer spans and other features not feasible with other materials.
- CFS has a high strength-to-weight ratio, up to 25 times greater than wood. Less steel is needed to bear a specific load than other materials resulting in a lighter frame.
- It is non-combustible and so decreases your insurance rates and builder's risk.
- No pests can chew through steel.
- It is resistant to corrosion and releases no volatile organic compounds.
- Steel can withstand high winds and seismic activity.
- Steel is a highly sustainable material - it is 100% recyclable and most of the existing steel contains a high proportion of recycled steel.
- Metal is durable and will last for decades with little maintenance.
The foundation for a building framed in CFS will cost less than for a heavier frame such as wood because it has less weight to hold. CFS is also ideal for soil conditions that would ordinarily limit a structure’s size and weight.
Because cold-formed steel is created under stringent factory conditions, the material is remarkably consistent with a high degree of precision in its manufacture. This precision and consistency translate into less cutting on-site and little to no scrap to haul off.
What Are Some Advantages of Using Cold-Formed Steel?
Using cold-formed steel provides multiple advantages over other framing materials, not the least of which is its ease of fabrication in mass quantities. Since it is manufactured off-site, there is no need to store large volumes of materials at the jobsite, reducing the need for security to keep vandals away.
- Cold-formed steel framing is easy to learn, reducing the need for highly skilled labor and reducing training time. Skills for using wood studs can be transferred to using steel C-section studs. Formed steel single tracks are similar to top and bottom wood plates.
- The number of tools required to work with CFS is relatively small, including tools such as an adjustable torque screw gun, a hand seamer, clamps and a magnetic level.
- Construction moves faster since there is little in the way of punching, cutting or drilling steel onsite. The CFS is easily moved and put into place with less need for heavy machinery.
- The site does not require heating to work with CFS as it does with CIP concrete.
The high precision achieved by automated processes is enhanced by the precision of a pre-engineered metal building. Pre-engineered buildings are fabricated by the manufacturer. Holes for fasteners are pre-punched and all metal is cut to length. Some parts come pre-welded or pre-assembled before shipping. Overall, a strict inspection is performed to ensure every component fits together perfectly before it reaches the jobsite.
All that’s needed is to anchor the primary frame to the foundation and assemble all the components. A structure that used to take months or years to complete can be completed in days or weeks.
Steel frames also allow for clear-span construction.
- You can design a wide open area unobstructed by columns.
- The interior of a clear-span building can be configured and reconfigured to meet a variety of needs and activities.
- With no load-bearing walls, spaces can be carved out using lightweight partitions for walls that are easily moved about to create different sized rooms.
A final advantage to cold-formed steel is its broad acceptance throughout the industry. As CFS is used more often, more workers will pick up the skills needed to install it, making it easier to find labor. Building inspectors also become more familiar with the characteristics and strength of cold-formed steel, speeding up the inspection and approval process, as well as the permitting process.
Cold-formed steel has become the preferred material for steel-framed construction. Prefabrication, in particular, benefits from cold-formed steel. Nearly all secondary framing members are premanufactured using CFS and manufacturing is not disrupted by the weather as it could be if all steel forming were limited to the jobsite.
Cold-formed steel provides all the same benefits and advantages as structural steel, including the ability to recycle it instead of placing scraps or removed members in a landfill. Transportation costs and reduced with the lighter weight of CFS over wood or preformed concrete as well as the reduced need for haul-off from the site.
When components go together as quickly and easily as they do with a pre-engineered building made of cold-formed steel, there is less risk of injury to workers as well as fewer days of labor required onsite. The shorter timeline is less affected by weather and other disturbances so that the building project can proceed apace.
Once a building project is complete, nobody will be able to see the members holding it erect, but you will know they are made of the strongest, most durable construction material on the market.