Care should be taken in the design of a fire resistant assembly, for the simple reason that to remedy incorrect procedures can be costly. It is the model structure codes that are able to distinguish the requirements of the fire-resistance for any structure that is based first and foremost on many different factors. These factors will include, but are definitely not limited to all the types of occupancy, for example business and assembly. The size of the building is also included, like the area and height, so also the type of construction you are dealing with and also the location of the building premises.
Fire insurance evaluation should be done beforehand, taking into consideration the agent’s as well as the building code’s requirements. Consider the protection needed for the assembly after fire resistance requirements have been established. This protection can either be direct fire resistance application or membrane protection, such as protection provided by the ceiling of a structure. Applied fire protection is obtained by spraying the steel joists directly with fire proof material. The selection of roof and floor types should be considered next. Lightweight concrete can be used for the construction of the floor and a rigid insulation for the roof.

Requirements for all materials to be used in the construction of a fire proof building can be obtained from the Fire Resistance Directory. The UL Fire Resistance Directories requirements must be met, and that includes the joist depth as well as the “per foot weight”. A selection of the right material can be made quickly if the right procedures are followed. SJI’s Technical Digest No. 10. “Design of Fire-Resistive Assemblies with Steel Joists” will supply all the answers to the designer or professional builder.