2012 ASD/LRFD Manual for Engineered Wood Construction

36 M7: PREFABRICATED WOOD I-JOISTSFigure M7.4-4Web Stiffener Bearing InterfaceBeveled End CutsBeveled end cuts, where the end of the joist is cut on anangle (top flange does not project over the bearing, muchlike a fire cut), also requires special design consideration.Again the severity of the angle, web material, location ofweb section joints, and web stiffener application criteria effectthe performance of this type of bearing condition. Thespecific wood I-joist manufacturers should be consulted forlimits on this type of end cut.It is generally accepted that if a wood I-joist has theminimum required bearing length, and the top flange of thejoist is not cut beyond the face of bearing (measured froma line perpendicular to the joist’s bottom flange), there isno reduction in shear or reaction capacity. This differs fromthe conventional lumber provision that suggests there isno decrease in shear strength for beveled cuts of up to anangle of 45 o . The reason involves the composite nature ofthe wood I-joist and how the member fails in shear andor bearing. Figure M7.4-5 provides an illustration of thebeveled end cut limitation.Figure M7.4-5Beveled End CutAMERICAN WOOD COUNCIL