In the age of sustainability, architects, designers and engineers aim to deliver beautiful, environmentally sound structures for their clients. What sustainability options do they have with cold-formed steel (CFS) framing?
CFS framing helps projects “earn green” in general. But an even bigger green payout comes by using nonstructural EQ or “equivalent” CFS studs. EQ products make more efficient use of steel.
What are EQ studs all about?
Less steel, same structural integrity
Pre-punched holes facilitate the installation of electrical wiring, plumbing, and bridging without having to cut holes on the job site.
Steel is Earth’s most recycled material, and EQ studs make the sustainability efforts of the steel industry even better.
Each year, the steel framing industry buys massive amounts of steel, rolled each year into millions of lineal feet of CFS studs for use in construction.
- How can CFS producers reduce their hot-dipped galvanized steel input amounts, while maintaining overall industry capacity?
- How can CFS designers create more efficient non-load-bearing, nonstructural CFS-framed walls?
The answer lies in nonstructural EQ CFS studs. Such studs feature today’s advanced steel formulations and shapes. They meet similar limiting heights as do tried-and-true 18 mil (25 gauge) and 30 mil (20 gauge) studs.
Standard RC-1 channel EQ studs, made from high-strength steel, are perfect for interior walls with specific sound transmission coefficient (STC) ratings.
So, designers and contractors can use nonstructural EQ CFS studs to build the same assemblies they always have and save material. EQ stud assemblies weigh less, and will probably cost less, too.
EQ studs vs standard studs
Nonstructural EQ studs take advantage of the availability to roll steel with a higher yield strength (ksi) than traditional steel formulations.
“Improvements in manufacturing technology and a redesign of the basic stud profile along with changes in the strength of steel used to manufacture EQ thickness studs resulted in products manufactured to a thickness less than the ASTM [C645] specified 18-mil, but which attained the same or greater limiting heights as standard thickness members,” says Greg Ralph, vice president of business development for ClarkDietrich Building Systems, in Cold-Formed Steel Was Great Yesterday, Even Better Today published by Design and Build with Metal.
“The [EQ steel] members have better screw shear and pullout values per higher strength steels used in the manufacturing of the EQ thickness studs,” he adds.
Life safety is a primary concern of all design and construction professionals, and bending strength is an important criteria for a wall or ceiling assembly’s overall strength. AISI defines bending or flexural strength for interior drywall framing members by Allowable Moment. Note this comparison:
Steve Farkas, Director of Business Development at CEMCO, provides this stud comparison in the Walls & Ceilings article, Sustainability and the Rise of “EQ” Nonstructural Framing Systems: to illustrate the environmental savings EQ studs can provide.
Comparing a standard 3-5/8” 30 mil (20 gauge) stud (362S125-30 ksi) with the ViperStud® (20EQ, 362VS125-18-70 ksi) produced by CEMCO, architects could help cut back on the amount of steel used on their projects by choosing the latter EQ stud. The savings could potentially be staggering.
Pounds of Steel Saved
* Data courtesy of CEMCO
Standards are changing
So, how do architects, designers and engineers specify EQ studs for their assembly designs? Look to the new, American Iron and Steel Institute (AISI) S220 standard.
“The latest version (2018) of the IBC makes no reference to ASTM for nonstructural framing,” says Robert Grupe, director of technical services at the Association of the Wall and Ceiling Industry (AWCI) in Codes and Standards in Transition published recently in AWCI’s Construction Dimensions. “The new referenced standard is AISI S220, North American Standard for Cold-Formed Steel Framing – Nonstructural Members.”
Thus, it’s important to keep up with the changes in standards and codes currently underway.
Nonstructural EQ framing products save steel while still satisfying design requirements. Have you made EQ studs a top-priority on your commercial, industrial, mid-rise and residential projects?