The Third Edition is based on the 2004 Supplement of the 2001 North American Specification for the Design of Cold-Formed Steel Structural Members. The manual explains the method developed to calculate the capacity of diaphragms using steel roof decks or composite steel floor decks and the use of the diaphragm load tables.

The diaphragm tables have been revised and adapted for ease of use with either the allowable stress design (ASD) or load and resistance factor design (LRFD) methods according to the North American Specification for the Design of Cold-Formed Steel Structural Members. With over 130 pages of diaphragm load tables using welds, screws and other mechanical fasteners, the manual is a comprehensive resource for the design profession. There are 16 example problems for ASD and LRFD design and equations to check fasteners for the combined effect of shear and tension.

Please Note:
A few unexpected editorial changes in DDMO3 have resulted in a delay in the release of this manual until December 2004. We apologize for this delay. Please continue to monitor the SDI web site at www.sdi.org for complete details.