The North American Steel Framing Alliance has announced the International Code Council, publisher of the International Residential Code and International Building Code, has made a favorable code change for steel, allowing the use of gypsum wallboard for shear resistance in seismic areas. This change will be published in the 2002 IBC Supplement.
Significant for steel framing, the revised code permits the same sheathing guidelines used for wood framed systems can now be used for steel. A steel framed system will be subject to the limitations in Table 1617.6, lines 1.L and 2.U, meaning it must be designed with an R factor of 2 or 2.25 and are permitted to a height of 35 feet in Seismic Design Category D, and prohibited in Seismic Design Categories E and F. These revised code limitations are specific to the sheathing materials used, including plywood, OSB and gypsum wallboard.
"We are pleased with the outcome of this code revision and are encouraged by the ICC's action taken on this issue," said Hank Martin, director of construction codes and standards for the American Iron and Steel Institute, who spearheaded the code revision with research data from NASFA. "Prior to the code change, under Seismic Design Category D, the code did not allow for the shear capacity of the drywall on steel framed systems to meet shear code requirements. Now they are allowing it."