In my current column in USGlass Magazine, I addressed the topic of flush bolts installed on the inactive leaf of a pair of doors. Do you know the answer to this question:
On pairs of doors, are inactive leaves that are not required for egress allowed to have manual flush bolts?
According to the International Building Code (IBC), the answer depends on the use group, the calculated occupant load, and whether the building has a sprinkler system. If you’re not sure when and where manual flush bolts are allowed, check out the post on the USGlass website!
USGlass Magazine is the largest trade publication that specifically serves the architectural glazing industry. From manufacturing and fabrication, to distribution and installation, the magazine covers all facets of the industry – including the code requirements that apply to these openings! As the list of my monthly posts grows, you can click here for the whole library. 🙂
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Good Day Lori,
Manual FB can be used on fire-rated doors up to 8-0 in height (top being 24″C/L down on 8-0 & 12″ C/L down on 7-0)
Doors over 8-0 where FB is used, only auto FB can be used.
Excerpt below from our (Daybar) 90 min 8-0 x 10-0 pair.
Option 2:
Listed fire rated Yale 8700/8800 Series Mortise Lock with a ¾” latch throw and a listed fire rated Von Duprin Auxiliary Fire Latch (top of leaf), (Active Leaf).
Listed fire rated DCI 840 Series Automatic Flush Bolts installed on the top and bottom (Inactive Leaf)
A listed and labeled door to door fire pin is required to be installed between the bottom of the active leaf and the inactive leaf. The fire pin may be installed in either the active or inactive leaf. Please consult the manufacturer’s listed installation instructions.
14 Gauge Astragal is Required.
NOTE: When utilizing this locking hardware configuration with the Daybar Industries Ltd. 45 – 180 Minute Fire Rated Honeycomb Core Steel Fire Doors (Neutral Pressure), the maximum fire rating shall be reduced to 90 minutes (neutral pressure).
Ratings: 45 – 180 Minute Neutral Pressure Doors
Note: Rating is dependent on latching configuration. Please see restrictions for more information.
Thanks for your comment, Brian. In addition to the egress requirements related to manual flush bolts, the use of manual flush bolts on fire doors depends on what type of room the pair is serving. NFPA 80 states that manual bolts may be approved by the AHJ if the pair of doors is serving a room that is not normally occupied by people, however, the IBC does not include this exception, so it would require AHJ approval. If the pair of doors to a mechanical room, for example, is located in the corridor wall of a health care facility, both leaves of the pair are required to have positive latching hardware, so manual flush bolts would not be allowed there (whether the door is fire rated or not).
– Lori