9.9.4.3. Wired Glass or Glass Block

 9.9.4.3. Wired Glass or Glass Block 

This Article provides the requirements for the properties and size of wired glass and glass block that are used to reduce the risk of heat radiation from a fire on a floor area that can make an exit stairway unsafe for evacuation if the exit is not shielded by a fire-resisting vestibule.

Glass block or wired glass can withstand the effects of fire long enough to permit its use as a closure. Large glass areas, however, can expose the exit user to radiation from fire in the adjacent floor area. For this reason, the area of glass in the doors of an exit (and any adjacent sidelight) must be limited, unless the exit door is protected by an enclosed corridor or vestibule separated from the floor area by fire separations having not less than a 45 min fire-resistance rating (Figure 9.9.-2).

Quoted from Illustrated Users' Guide - NBC2015