The traditional fire exposure in fire tests used to evaluate the performance of construction materials is the standard time-temperature curve specified in ASTM Fire Tests of Building Construction and Materials (E 119-80). There is growing concern that the severity of a fire defined by ASTM Method E 119-80 may not be representative of most fires which occur in buildings such as offices, schools, hotels, apartments, and other similar occupancies. Extensive research on postflashover conditions in building compartments supports this concern. However, the heating conditions in ASTM Method E 119-80 are not appropriate for exterior structural members. Therefore, research described in this paper provides a simple method for describing fire exposure of structural members located outside the enclosing walls of buildings.

The following procedure establishes the intensity of the fire in the compartment under ventilation-controlled or free-burning conditions, the shape and size of the flame emerging from openings in exterior walls of the fire compartment, and the temperature of the flame, all of which are needed to calculate the heat transfer to structural members outlined by the American Iron and Steel Institute.