flush-boltOne of the cardinal rules of fire doors is that they are required to be positive-latching – there must be an active latchbolt that automatically latches the door when it comes to a close.  For pairs of doors this typically means that automatic flush bolts must be used, but NFPA 80 includes a potential exception to this rule – manual flush bolts may be used on pairs of fire doors leading to rooms that are not normally occupied by people (where acceptable to the AHJ).  I have mentioned this before, but I still get questions on this topic so here’s some more info.

First a few important points…

  1. For health care occupancies, NFPA 101 requires corridor doors to be self-latching, including a specific requirement for automatic flush bolts on the inactive leaves of pairs, so the NFPA 80 exception for manual flush bolts does not apply to health care corridor doors.
  2. For elevator machine rooms, refer to this blog post, which addresses the need for positive-latching hardware on these doors.
  3. In many occupancies, manual flush bolts are not allowed in a means of egress.  In my opinion, this limitation would not affect rooms that are not normally occupied by people, but here’s an article that covers the egress aspect of manual flush bolts.
  4. If you’re looking for some basic information about flush bolts, this video might help.

And now…back to NFPA 80.  This is from the 2016 edition, but the language hasn’t changed in recent prior editions:

6.4.4.5.1* Manually operated, labeled, top and bottom flush-mounted or surface-mounted bolts on the inactive leaf of a pair of doors shall be permitted to be used where acceptable to the AHJ, provided they do not pose a hazard to safety to life.

From Annex A – Explanatory Material:

A.6.4.4.5.1 This provision limits their use to rooms not normally occupied by humans (e.g., transformer vaults and
storage rooms).

The next question is whether the inactive leaf of a pair of fire doors leading to a room that is not normally occupied by humans is required to have a door closer.  Since the inactive leaf doesn’t automatically latch when it closes, I think a closer could almost be detrimental here as the door could be closed and presumed latched even though the bolts are not projected.

NFPA 80 states:

6.4.1.1* Unless otherwise permitted by the AHJ, a closing device shall be installed on every fire door.

The exception that applies to this application is in Annex A:

A.6.4.1.1 It is the intent of the standard that most fire doors will have a closing device. However, in limited circumstances the closer might not be necessary because the door leaf is inactive and is normally in the closed position. Examples of such applications include pairs of doors to mechanical equipment rooms and certain industrial areas where an inactive leaf is provided and is infrequently used to permit large equipment to be moved through the door opening. In such instances, the AHJ should be reasonably assured that the inactive leaf normally will be closed and latched…

So here are the questions for you…

  • What do you typically specify for the inactive leaf of a pair of fire doors leading to a room that is not normally occupied by humans? 

  • Do you request prior approval from the AHJ when specifying manual flush bolts on fire doors? 

  • Have you ever had an AHJ reject the use of manual flush bolts on these doors?

  • WWYD?

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