Patent attributes
Fire resistant door, glazing, and mullion frames include intumescent material at least partially embedded in the frame adjacent the door or glazing. Trim materials are positioned over the intumescent material to prevent tampering with and damage to the intumescent material while improving the aesthetic appearance of the frame. The jamb trim has a thickness that allows heat to be transmitted to the intumescent material in the event of a fire so that the intumescent material will expand and fill a clearance space between the frame and the door or glazing. The expanded intumescent material retards the passage of heat and, by sealing the clearance space, inhibits the transmission of smoke, flames and gases from one side of the door or glazing to the other. After expanding, the intumescent material will char and solidify, which may provide an added benefit of structural support for the door or glazing.