What hardware is specifically required for a fire door?

The requirement for hardware specific to a fire door is centered around both safety and functionality during a fire situation. An active latch bolt is integral for fire doors because it ensures that the door will latch securely and remain closed under fire conditions. This is critical for maintaining the integrity of the fire-resistance rating, preventing the spread of smoke and flames between compartments.

An active latch bolt typically includes a mechanism that securely engages when the door is closed, automatically ensuring that the door remains latched without the need for manual locking. This automatic engagement is essential in emergency situations, where time is of the essence and a door must not inadvertently be left unlatched.

In contrast, while deadbolts, spring latches, and mortise locks may provide security in various door applications, they do not meet the specific requirements necessary for fire doors. Deadbolts may require manual operation that could lead to a door being left unlocked. Spring latches may not provide the necessary hold under fire conditions. Mortise locks, while robust, are not specifically designed to meet fire door requirements without additional features that allow the door to function appropriately in a fire situation. Thus, the active latch bolt stands out as the appropriate choice for ensuring the continued efficacy and safety of a fire door.