AISI Publishes North American Standard for Cold-Formed Steel Framing-Lateral Design 2007 Edition

WASHINGTON, D.C., June 21, 2010 – The American Iron and Steel Institute (AISI) has published AISI S213-07-S1-09, North American Standard for Cold-Formed Steel Framing—Lateral Design 2007 Edition With Supplement No. 1 to incorporate research findings on diagonal strap-braced walls, along with other updates. AISI Standard S213 addresses the design of lateral force-resisting systems to resist wind and seismic forces in a wide range of buildings constructed with cold-formed steel framing. It provides an integrated treatment of Allowable Strength Design (ASD), Load and Resistance Factor Design (LRFD), and Limit States Design (LSD).

The Standard was approved by the American National Standards Institute (ANSI) as the American National Standard, was adopted by the National Building Code of Canada (NBCC), and is intended for adoption in Mexico. The Standard with Supplement No. 1 and Commentary is available for purchase on the Steel Framing Alliance website at www.steelframing.org.

In addition to incorporating research findings on diagonal strap-braced walls, other major changes in Supplement No. 1 include:

  • Rd  values in Table A4-1 for diagonal strap-braced (concentric) walls were adjusted to match the values approved by the Canadian National Committee on Earthquake Engineering (CANCEE) for inclusion in the National Building Code of Canada seismic provisions.

  • Language in C1.1 was modified to clarify when design must comply with the special seismic requirements.

  • The existing provisions on setbacks in Section C2, which the AISI Committee on Framing

Standards thought should be limited to prescriptive methods with defined limits of applicability, were replaced with a requirement deemed to be more appropriate for a design standard.

  • Adjustments were made to Table C2.1-3 for 0.027” steel sheet, one side, based on testing at the University of North Texas (Yu, 2007). The designation thickness for stud, track and blocking associated with the existing tabulated values was increased from 33 mils (min.) to 43 mils (min.). New values were added for designation thickness for stud, track and blocking equal to 33 mils (min.).

  • Equation C2.1-1 for determining the design deflection of a blocked wood structural panel or sheet steel shear wall was consolidated for U.S. Customary and SI units.

  • The word “countersunk” was deleted and commentary added to clarify provisions for tapping screws to attach wood structural panel sheathing in Section C2.2.2.

  • Language in C3.3.2 was modified to clarify when the uplift anchorage and boundary chords must comply with the special seismic requirements.

  • The design provisions of Section C5.3, Seismic Forces Contributed by Masonry and Concrete Walls and Section C5.4, Seismic Forces from Other Concrete or Masonry Construction were relocated under Section C1, General.

  • A definition for amplified seismic load was added under Section A2, Definitions.

  • Equation D2.1-1 for determining the design deflection of a blocked wood structural panel diaphragm was consolidated for U.S. Customary and SI units.

The Commentary illustrates the substance and limitations of the various provisions of the Standard and provides background information related to the revisions included in Supplement No. 1 of the Standard.

“The North American Standard for Cold-Formed Steel Framing—Lateral Design 2007 Edition With   Supplement No. 1 and Commentary was developed and published by the AISI Committee on Framing Standards, which includes engineers, researchers, producers and others who contribute to the body of knowledge on the subjects,” Jay Larson, P.E., F. ASCE, managing director, AISI Construction Technical Program, said. “We appreciate the work of each of the committee members and the support of the Steel Framing Alliance and Canadian Sheet Steel Building Institute in bringing these documents to the marketplace.”

AISI’s codes and standards work is conducted under the Construction Market Council of the Steel Market Development Institute (SMDI), a business unit of AISI. The SMDI oversees the industry’s investment in advancing the case for steel in the marketplace as the preferred material of choice.  AISI serves as the voice of the North American steel industry in the public policy arena and plays a lead role in the development and application of new steels and steelmaking technology. AISI is comprised of 23 member companies, including integrated and electric furnace steelmakers, and 138 associate and affiliate members who are suppliers to or customers of the steel industry. AISI’s member companies represent approximately 75 percent of both U.S. and North American steel capacity. For more information, visit www.smdisteel.org

Contact:
Debbie Bennett
Manager, Communications
Construction Market
Steel Market Development Institute
Tel: 202.452.7179