The Design of Fire Resistive Assemblies with Steel Joists provides structural designers and specifiers with guidance on selecting and modifying fire‑resistive floor/ceiling and roof/ceiling assemblies that incorporate steel joists. It reviews fire‑resistance ratings, explains how to interpret test results and listed assemblies from the Underwriters Laboratories (UL) Fire Resistance Directory, and offers step‑by‑step procedures for adapting or substituting joist types (such as K‑Series in place of S‑, J‑ or H‑Series joists) while maintaining required fire endurance. It also includes a comprehensive appendix listing UL‑rated assemblies with steel joists—organized by hourly rating, protection type, insulation, deck type, and minimum joist size/spacing—so that designers can efficiently locate suitable assemblies for their projects.