Fire Curtains are often compared to fire doors. While they perform the same job, placing a UL-rated opening protective across an opening in a rated wall, they differ drastically in composition, arrangement, control, and testing to assure consistent performance across opening protective technologies.
Though fire curtains don’t swing as an overall assembly as fire doors do, they sometimes include passageways for egress that are tested to stay closed during the same 20 Pa pressures as their UL testing. This closure is done by mandating a designed overlap between the multiple rollers of the system.
This overlap varies between manufacturers but is usually 10″ – 24″, and hinging the weighted bottom bar in the correct offset location allows a person to push through that overlap unobstructed.
This egress within the opening protective curtain, though sometimes called “swinging door,” is really taking advantage of the principle that the curtain technology can pass UL testing and provide fire protection without a physical linkage between the overlapping components. Curtain material is lightweight compared to the bottom bar, so it stays closed at UL pressures.
“According to Section 7184.108.40.206 from the IBC, Door Closing requires doors to be latching and self/automatic closing. How does Fire Curtain Technologies comply?”
The code reference §7220.127.116.11 is a requirement for swinging fire doors. That is to say that once their mag-hold has released and they’ve swung closed, they must latch to stay closed when exposed to a 20 Pa pressure differential – about 15lbs on a standard single-leaf door. 15lbs happens to be the max push-force for egress, so they must latch in order to meet both requirements.
In resume, whatever your opening protective is, it must stay closed once closed at required pressures, unless an occupant would like to pass through.
Are you interested in using fire curtains with egress in your next project? The Fire Curtain Technologies team of engineers is ready to help you find the right option. We provide design and code compliance support free of charge