Provided by: APA - The Engineered Wood Association
Date Added: Feb 2005
Tests show Narrow Wall Bracing Method (a portal-frame structure) performs comparably to existing code permitted bracing for residential structures when built on rigid foundations or raised wood floor assemblies. Section R602.10.5 of the 2003 International Residential Code (IRC) permits a 4:1 aspect ratio for narrow wall segments constructed with no hold-down devices when the home is fully sheathed with wood structural panels and the narrow wall segment is adjacent to a limited-height window. More than 25 full-scale cyclic tests in two phases demonstrated that 6:1 aspect ratio portal frame design performed comparably to the IRC's provisions.