Intumescent seals or gaskets are not required on fire rated steel doors.
Generally speaking, the requirement for intumescent seals or gaskets are a function of the individual manufacturers’ listi...
Maximum UL Fire Rated door sizes are as follows:
A-Series:
4' 0" X 8' 0" single door
8' 0" X 8' 0” double door or pairs
B-Series
4' 0" X 10' 0" single door
8' 0" X 10' 0” double doo...
ITS/WHI is "Warnoch Hersey". ITS/WHI is the formal designation for Intertek Testing Services / Warnock Hersey. ITS/WHI is an independent agency with testing, listing, in-plant inspection, and label...