Fireproofing involves preparing a surface or structure such as an electrical, water or steam conduit path or other critical resource with specialized insulation which may or may not include encasement in cement structures. It is a passive mechanism designed to retard but not eliminate the ability of the surface or structure to catch or propagate fire. In circumstances where a coating is appropriate prior to encasing in cement, the coating is applied and then forms are constructed for the encasing structure. Cement is then poured and the form removed once the cement has cured in final form.
This was the regime during the construction of the backup power plant on the roof of Five World Trade Center where the feeder utility corridors were fireproofed and encased in cement as the conduit traversed throughout the World Trade Center’s underground parking lot.