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The door to fire safety.

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. A typical door opening would not have materials stacked on either side, and the exposure to fire would be reduced.

Lower fire door rating classifications typically available in North America include one-and-one-half hour, forty-five minute, and twenty-minute doors. Doors with the one-and-one-half hour classification are used to limit the spread of fire to a particular area of the floor, such as a stairwell. A forty-five minute door or the twenty-minute door could be installed in a corridor, where it would be used to prevent smoke from a fire in a small office or a hospital patient room from filling the hall.

Twenty-minute doors are often referred to as smoke doors, and some localities require only that they be self-closing and sealed. A latch may not even be required, as the door's purpose is to stop the spread of smoke.

Sub-classifications, which are identified by letters of the alphabet, indicate that the doors and hardware meet additional requirements. Sometimes the classification for a one-and-one-half hour door, which is a B on the interior, would be changed to another letter if used on an exterior.

Some manufacturers have hardware or doors and frames that can be built with larger dimensions for shorter time durations. A manufacturer may have an exit device that has a three-hour rating for 7'2" doors, but the same exit device with only a minor change may be available for 8' doors if used for a one-and-one-half hour application.

A security manager hoping to stay with one manufacturer for all the fire exit devices in a building should look for a manufacturer that can meet the building's most stringent requirements. If the building has high, wide doors through which equipment will have to be moved, the manufacturer should be able to provide several appropriate product solutions.

Some manufacturers offer a three-hour rating on a pair of doors that are 9'3" x 8'. For an industrial or research facility, the requirements to move large equipment are not unusual. Fire-rated exit devices are available for doors up to 10' high.

When looking at the requirements for fire exit devices, it is important to realize that a manufacturer may have a rim device suitable for a 8' x 4' door, but on a pair of doors, the same manufacturer's vertical rod exit device may only be rated for a 7'2" x 4' door. While a rim device can be used with a single door that is 8' x 4', it is not possible to meet fire regulations by simply installing a pair of the same doors and hardware.

Another problem occurs when inappropriate hardware is installed on labeled doors. For instance, the UL 1991 Mechanical Equipment Handbook lists a product known as an exit lock. This device is not a fire exit device or a panic exit device. It simply sounds an alarm when someone tries to use the door without disarming the system. Even on a fire door that does not require a panic fire exit device, this type of device does not self-latch and would not be allowed to be used in a facility. MANY PROBLEMS DEVELOP when doors that were correctly equipped for the situation when the building was designed are modified in the field. Normally, an astragal is put in when a pair of fire doors are installed, because many fire doors require the protection of an overlapping astragal to pass the test for a three-hour fire label. An astragal might be added to a pair of doors equipped with vertical rod devices to help restrict light, sound, or weather. In an emergency, the astragal would restrict one of the doors from opening and may cause individuals to be trapped.

Although they often have astragals, exterior doors of a facility being modified seldom are fire doors. Fire-rated doors are installed in fire walls to separate areas of a building and prevent the spread of a fire, as well as to protect paths of egress, such as corridors and stairwells. Unless an exterior door opens from a stairwell, it is most likely a panic exit rather than a fire exit. Single doors equipped with panic devices can use either rim-type or mortise locks, depending on the door and frame preparation. Most manufacturers do not test vertical rod exit devices on single doors, so they may not be labeled for that specific application.

Double doors with mullions can be equipped with hardware exactly like a single door, normally using a rim exit device on each. Another type of double-door layout is a double-egress arrangement, with one door swinging in and the other swinging out. These doors are each equipped with an exit device on opposite sides, so an individual approaching from either side would only see one exit device and be guided to the proper door.

Any doors with fire labels are required to be self-closing and self-latching to contain a fire if one occurs. In some cases, a wall-mounted, hold-open magnet or door closer with a hold-open feature can be used if it is tied into the fire alarm. These must be wired so that any power interruption will cause the doors to close automatically. Kick-down door stops should never be used on a fire door. This is a common retrofit error and can cause serious repercussions in the event of an emergency.

Although the NFPA code calls for one knob, handle, panic bar, or other simple type of releasing device that is easy to operate under all lighting conditions, doors continue to be equipped with multiple locks in the name of security. Under adverse or emergency conditions such a door might be the only way out, but in smoke, fire, or darkness, people could easily be trapped without any direction on how to escape.

In some cases, extra hardware is added for aesthetic reasons. This, too, can be confusing. A set of double doors that aid in moving large equipment might be equipped with a nonfunctional doorknob on the second door in addition to automatic flush bolts. Someone unfamiliar with the door could be confused by the doorknob in an emergency and unable to exit the facility at all.

Many other mixed installations occur through improper maintenance or careless retrofit procedures. Misadjusting or removing one of the vertical rods on a fire-labeled door destroys the latching necessary for fire integrity.

Adding hardware store-type dead-bolts may improve security at the expense of fire safety. Doorknobs that can be operated by the average person may stymie a senior citizen, a child, or a person with a disability. Chaining an exit violates any fire code.

Special locking arrangements, such as delayed exit devices allowed under the NFPA code, should take care of most security needs without jeopardizing safety.

Whenever remodeling or retrofitting work is done, especially when a building or area is being converted for a different use, paths of egress should not be compromised. This would invalidate the rating of a labeled or emergency exit door. Even if local codes do not require a permit for the work, the company is responsible for the continued safety of the building and its occupants.

S. Carl Dean is sales development manager for Von Duprin, Inc., a division of Worldwide Ingersoll-Rand in Indianapolis, Indiana.
COPYRIGHT 1993 American Society for Industrial Security
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 1993 Gale, Cengage Learning. All rights reserved.

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Title Annotation:Fire Safety; fire doors; building security and life safety
Author:Dean, S. Carl
Publication:Security Management
Date:Oct 1, 1993
Words:1869
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