IBC-compliant, steel welded egress stair systems consisting of pre-fabricated landing, stringer, tread, and rail components that are easily customized to meet specific project requirements. Our commercial steel stairs are a complete outsource solution that includes estimating, design, detailing, and dedicated project management. IBC-compliant.. IBC Stair handrails have multiple horizontal stair rails and a grip rail, at least three for Commercial Stairs.IBC stairs climb at 30 degrees maximum and have minimum 11" deep treads. Residential Stair code and California Building Code have a 4" sphere rule for Residential stair use. IBC stairs have a 4" maximum riser openings but usually require closed stair risers. IBC Codes regardIng. The information available here offers Architects, Engineers, General Contractors, Installers and Students general guidelines for steel stair egress systems. The information and details provided here are designed to meet the 2015 International Building Code (IBC). Design changes may be required depending on your projects region. The stair tread code requirements are also slightly different, with a minimum depth of 11 inches. For both of those codes, the maximum tolerated difference in height and depth is 3/8 of an inch, the same as for residential stair code measurements. Another stair specification section by the IBC commercial stair codes is that stair tread nosing.