Scope and Purpose of the Guide
This guide has been prepared to assist practicing structural engineers to design cold-formed steel framing (CFSF) systems. This is the second edition of the Guide-the first was published January 2002 (AISI 2002a).

A general review of the basic structural principles is provided along with a number of detailed design examples covering wind bearing and axial load bearing stud walls and joists. The design examples are based on the 2001 North American Specification for the Design of Cold-Formed Steel Structural Members (AISI 2001a) and the Supplement 2004 to the North American Specification (AISI 2004). Reference is also made to ASCE 7-05 (ASCE 2005) and the 2006 International Building Code (IBC 2006). The examples show how to translate the information available in load tables into complete structural systems. Both screwed and welded connection details are included with an emphasis on screwed. Useful information on the strength of commonly used concrete anchors and self-drilling screws is also included.

A number of methodologies are proposed to handle design problems not covered in the AISI Specification. These include a rational method to check the warping torsional stresses in channel members, an approximate method to check the bearing stresses under the bottom track of axial load bearing stud wall assemblies and a method to check the strength and stiffness of inner and outer top track assemblies for wind bearing applications.

A universal designator system for Cold-Formed Steel Framing (CFSF) members has been used throughout the Guide. This product identification method is described in Appendix I.

Changes from the 1st Edition of the Design Guide
The first edition of the Design Guide (AISI 2002a) has been completely rewritten to reflect improvements in the design of CFSF members and connections.

• The load combination factors as required by ASCE 2005 have been used including a 0.7 factor on wind for deflection calculations from IBC 2006.
• The design examples have been revised to conform to the latest design standards including the AISI Specification (AISI 2001a) and the AISI Supplement (AISI 2004). In addition, AISI/COFS standards have been used where applicable (COFS 2004a), 2004b and 2004c).
• Power actuated fasteners have been added to the examples.
• A single outer top rack deflection detail has been added.
• A slide clip detail for connecting wind bearing jamb studs has been added.
• A design methodology for flat strap blocking-in has been provided.
• Design Example #2 has been expanded to include both welded and screwed connections.
• The design method for checking cantilevering stud deflections has been expanded.
• An alternative parapet design using cantilevering HSS posts has been added.
• The connection details in Design Example #4 have been converted from welded to screwed to reflect the more common practice.
• A jack stud has been added to the built-up jamb detail in Design Example #4.
  

Load Tables

In the first edition of the Guide, the generic load tables prepared by the Steel Stud Manufacturers Association (SSMA) were used as the source for section properties and floor and wall load capabilities. Generic tables based on the latest codes and standards (AISI 2001a, AISI 2004, ASCE 2005 and IBC 2006) were not available during preparation of this second edition and the output from industry standard software, AISIWIN (Devco 2006), has been used instead. Thus in the design examples were reference is made to “load tables” or “manufacturer’s tables”, it is actually AISIWIN output that has been used. Note that the AISIWIN output is to the 2001 AISI Specification (AISI 2001a) including the 2004 Supplement (AISI 2004).