Promat PROMATECT®-250 is a thin lightweight board product which can be used for this application to provide up to 120 minutes fire protection to steel. A single layer of 15mm PROMATECT®-250 can provide 60 minutes fire resistance to most steel sizes (depending on the steel section factor and limiting steel temperature). It can be installed as a single layer with no gap between the steel and the casing, so no additional space is required. In this instance, the fire protection to the steel would only require 15mm clearance around the steel section. More information can be found in the UL-EU 01220-CPR Certification document for PROMATECT®-250 structural steel encasements.