Magazine article Security Management

The Door to Fire Safety

Magazine article Security Management

The Door to Fire Safety

Article excerpt

WHEN IT COMES to fire doors, building security and life safety may operate at cross-purposes. An awareness of building code and fire labeling requirements helps in designing a security system that maintains fire-labeled door integrity.

A fire-labeled door is only effective if all elements of the door system are in place and operating properly. This requires the door's latching to withstand the labeled fire exposure. If a fire door is held open mechanically, if the latches are not engaged, or if a pair of doors closes in the wrong order, the door may not stop a fire from spreading. The best intentions in specifying and installing the correct systems are often foiled by poor adjustment, retrofit errors, or improper installation. The following typical situations illustrate what can be done to achieve security if labeled fire doors are to remain effective.

When a door and a frame both have fire labels, fire-rated hardware must be used if the opening is to remain a fire-rated exit. The hardware can be a fire-rated latch set or fire-rated exit (panic) device, but it must carry a fire label. This requirement precludes using an exit device with mechanical dogging, since a fire door must latch every time it is closed, although electrified door hardware, such as an exit device with electrical latch retraction, can be used. Electrically dogging doors in fire door applications can be used if they are wired to release the latch when the fire alarm system is activated in an emergency.

The National Fire Protection Association (NFPA) code clearly states that only one action can be required to unlock a door with exit or fire exit hardware. Yet, in attempting to improve security, companies still add self-contained add-on door alarms to doors already protected by exit devices. If all the lights went out during a fire or other emergency, these add-on latches would cause additional confusion to already panic-stricken people. Various types of delayed exit devices are available that combine secure locking and delayed release with safe and immediate egress in an emergency.

The fire code states that, "where pairs of doors are required as a means of egress, each door shall be provided with its own releasing device. Devices that depend on the release of one door before another shall not be used." Where pairs of doors have an overlapping astragal, which requires one door to open before another, hardware must be selected that allows either door to be opened quickly.

Using an exit device with a mortise lock on one leaf and a surface or concealed vertical rod exit device on the other allows the mortise lock to latch into the door with the vertical rod. Pushing on the mortise lock device opens that door. Pushing on the vertical rod device retracts the latches from the frame and the floor, allowing that door to open and the astragal to move the door with the mortise lock. A common mistake is to put vertical rod devices on both doors, causing the astragal on the outside of one door to stop the other leaf from opening.

If the code does not require both doors in a particular location to be equipped with exit devices, one may be equipped with flush bolts. A fire door requires automatic flush bolts, which keep the door locked whenever it is closed. Nonfire doors can be equipped with automatic or manual flush bolts depending on usage. A fire door coordinator (sequencer) must be used wherever a pair of doors has two types of hardware that requires sequential closing. An example is an exit device and automatic flush bolts or two exit devices and an overlapping astragal.

THE CLASSIFICATIONS for fire door ratings depend on the use, size, and occupancy requirements of different areas of the building. The highest rating, used to separate two major areas, is the four-hour wall with the three-hour opening (door). The wall is rated at four hours when it is expected that materials and goods could be stacked next to it. …

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