This post was printed in Doors & Hardware

Vertical rod fire exit hardware is available with top and bottom rods and latches, or with the top rod and latch only – known as “less bottom rod” or “LBR” devices.   Eliminating the bottom rods and latches can help to meet accessibility requirements and also allows the floor strikes to be omitted, but security may be affected so the application should be carefully considered.  LBR devices have been available from most panic hardware manufacturers for many years, but I still receive questions about them regularly – either related to the use of the product on fire doors, or their installation in a means of egress.

NFPA 80 – Standard for Fire Doors and Other Opening Protectives does not specifically address less bottom rod fire exit hardware.  The standard requires fire doors to be equipped with an active latch bolt to ensure that the door is positively latched during a fire.  Panic hardware used on fire doors must be fire exit hardware, which is not equipped with the mechanical means to hold the latch retracted (AKA “dogging”), and must bear labels from the listing agency for compliance with both panic and fire test standards.

Less bottom rod fire exit hardware has been successfully tested for use on fire doors, and the specifics can be found in the manufacturer’s literature or the listing agency’s directory of certified products.  For most applications, an auxiliary fire pin is required in order for the doors to maintain their fire resistance rating.  This pin typically mounts between 6” and 12” above the floor, on the edge of the door, although some manufacturers have tested their LBR devices without an auxiliary fire pin, or with pins mounted in the bottom edge of the door.  The pins remain retracted under normal conditions, and are heat-activated.  When the temperature of activation is reached – usually around 400 degrees, the pin projects from the edge of one door into a hole in the edge of the other door leaf (or into the floor if the pins are installed on the bottom of the door).  In addition to fire exit hardware, these auxiliary fire pins are sometimes used on fire doors with automatic flush bolts, when the bottom flush bolt is omitted.

The auxiliary fire pin has raised concerns about egress in the past, because once the bolt is projected, the doors no longer allow free egress.  It’s important to understand that the pin projects only during a fire, and its purpose is to maintain the alignment of the doors to prevent the spread of smoke and flames.   According to Underwriters Laboratories, an auxiliary fire pin with an activating temperature of 400 degrees typically projects 15-20 minutes into a fire test, when the temperature inside the test furnace is approximately 1,400 degrees Fahrenheit.  The pin is only actuated when the activation temperature is reached, and at that point the area would not be tenable for occupants or firefighters.

The tests used for fire door assemblies – UL10B, UL10C, and NFPA 252, do not require the doors to be operable at the conclusion of the test.  Most locks and exit devices incorporate fusible links which render the hardware inoperable during the fire test, so the doors remain latched throughout the hose stream portion of the test.  The auxiliary fire pin associated with less bottom rod exit devices operates under the same principal.

Another issue that has been raised is regarding firefighter access once the auxiliary fire pin has been projected after reaching the activating temperature.  In addition to the fact that most latching hardware is designed to become inoperable during a fire, the doors themselves (especially steel doors) are likely to become wedged into the frame.  The intumescent material required in some applications may also affect the operation of the door after a fire.  Firefighter access will require a halligan bar, even if an auxiliary fire pin is not part of the assembly.  And as one fire marshal commented, a door secured by a projected fire pin or inoperable hardware can be a warning to firefighters about the conditions on the other side of the door.

A change to the 2009 edition of the International Building Code helped to clear up some of the confusion about the egress requirements when these products are used on fire doors.  Paragraph 1008.1.9 Door Operations, states that egress doors must be readily openable from the egress side without the use of a key or special knowledge or effort, except as permitted by this section of the code.  Paragraph 1008.1.9.3 lists several exceptions where locks and latches shall be permitted to prevent operation of doors.  These exceptions include:

  1. Places of detention or restraint.
  2. Certain occupancies where key-operated locks may be used on the main entrance if certain criteria are met.
  3. Pairs with automatic flush bolts, with a requirement for the inactive leaf to be without hardware that would give the impression that the inactive leaf could be operated independently.
  4. Dwelling unit doors in Group R occupancies with an occupant load of 10 or less, where a night latch, deadbolt, or security chain may be used in addition to another lock.
  5. And an exception added in the 2009 edition of the IBC, states: “Fire doors after the minimum elevated temperature has disabled the unlatching mechanism in accordance with listed fire door test procedures.”  This exception has been included in subsequent editions of the IBC as well.

The purpose of Exception 5 is to address the use of fusible links and heat actuated components used in door hardware, including the auxiliary pin used with less bottom rod fire exit hardware.

Before removing bottom rods and latches from existing fire exit hardware, it’s important to check with the manufacturers of the fire exit hardware and the fire doors, and to follow the required procedures.  Doors that were installed before the introduction of LBR devices may not meet the fire test criteria for the use of the product.  Retrofit kits are available for some brands of hardware, and the kit may include replacement top strikes that need to be installed.  Removing existing rods and latches without following the proper procedures is likely to result in a fire door assembly that is no longer code-compliant.


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