Basic Life Safety Considerations for Door Hardware

With few exceptions, door hardware selection is dependent upon life safety considerations. When selecting hardware for doors that are considered on the "path of egress", it is helpful to keep certain principles in mind.

  • Exit must be accomplished by one motion
  • No prior knowledge can be required to exit
  • No key, card, or tool can be required to exit

Life safety is the purview of the local Authority Having Jurisdiction (AHJ), usually the fire marshal or building inspector. In order to avoid costly hardware replacement due to life safety code violations, it is best to run your hardware choices past your local AHJ in advance.

Mule Lighting Wet Location LED Exit Sign
Mule Lighting Wet Location LED Exit Sign
Sargent Rim Exit Device with "Sarguide" Illuminated Exit Signage
Sargent Rim Exit Device with "Sarguide" Illuminated Exit Signage

Path of Egress

When architects design a building, one of the features they design into the structure is paths of egress, which is to say routes by which people can get out of the building in the event of an emergency. Typically this route is indicated by exit signs as shown at right. Recently exit device manufacturers have begun to offer exit devices with luminous or illuminated exit signage to help make the path of egress more visible during an emergency in which, for example, the power might be out and smoke may be gathering near the ceiling, obscuring the view of the regular exit sign.

Typically path of egress doors are designed to open in the direction of the exit, meaning that people can push the doors and keep moving toward the exit in the event of an emergency rather than pausing to pull doors open as they go. Many jurisdictions require that path of egress doors swing in the direction of the exit.

Different jurisdictions may have different requirements for path of egress doors. Some inspectors will want an exit device; others may be happy with a cylindrical lever lock. An exit device, however, will almost always make a building inspector or fire marshal happy, and we like happy inspectors. Happy inspectors are a good thing.

Electromagnetic Hold Open
Electromagnetic Hold Open

Fire Rated Doors

Interior doors are often fire rated. Exterior doors are almost never fire rated.

Fire rated doors require fire rated hardware. The difference between fire rated hardware and regular hardware is that fire rated hardware has been tested by Underwriters Laboratories. I am told they test hardware on a 3-hour fire rated door, for example, by setting the door on fire and letting it burn for three hours and then hitting it with a stream from a fire hose, full blast. If the door opens, the hardware fails the test and does not get a fire label.

Fire rated hardware must remain positively latched in the event of a fire. That means, should there be a fire, the door must be closed. If you walk down a corridor in a hospital, you will see pairs of doors held open here and there along the path of egress. Chances are these are fire rated doors held back with electromagnetic hold open devices connected to the fire alarm. When the fire alarm is activated, it releases the electromagnetic door holder. A doorcloser must be installed on the door so that it closes automatically when it is released.

Usually the hospital double doors I mentioned will be equipped with fire rated concealed vertical rod devices, although sometimes they will have surface vertical rod exit devices. Usually these devices will not lock, but will only latch to comply with code. On the pull side, the devices are likely to be equipped with passage function levers, that is, lever trim that is always unlocked. That way it is possible to travel freely both ways through the opening. When the doors are shut by the fire alarm.

Where the path of egress is one way through the push side of the pair of doors, the oustide trim may be locked.

Most grade one mortise locks and cylindrical locks are fire rated and do not have to be specified as such. Use of mortise or cylindrical locks on egress doors instead of exit devices is subject to local building and life safety codes, so be sure to consult with your local AHJ.

Stairwell Doors

Many local codes dictate that at least some stairwell doors must be positively latched and unlocked in the event of a fire. This means that if you want access control on your stairwell doors, your options are limited. For example, electric strikes are out of the question, because if an electric strike were used, it would have to be both positively latched and unlocked in the event of a fire - an impossibility for a fail safe electric strike, as it would need to be.

A fire rated fail secure electric strike is fine to use on doors that are not stairwell doors, and can be used on stairwell doors that do not have to be unlocked in the event of a fire. In some jurisdictions, it is only every fourth floor that has to be unlocked in the event of a fire, not every stairwell door. Check with your AHJ to find out for sure.

The solution to this problem is either to use an electric lock for access control or an electromagnetic lock with the existing, non-locking fire rated lock or exit device already on the door.

I like the mag lock solution, but many inspectors do not. Be sure to check with your local AHJ before specifying an electromagnetic lock in any application.

For more information on electromagnetic locks, please visit:

http://hubpages.com/hub/Basic-Magnetic-Lock-System

For more information on electric strikes, please visit:

http://hubpages.com/hub/Choosing-an-Electric-Strike

For more information on electric locks, please visit:

http://hubpages.com/hub/How-to-Survey-a-Job-Site-for-Electric-Locking

A fail safe electric lock is often the more popular solution with the inspector, but the install is more difficult since a wire needs to be run through the door from the hinge side to the lock side. Technically speaking, this voids the fire rating of the door. The absolutely correct way to do is to take the door off and have it modified in a fire rated door shop. That said, installers are retro-fitting electric locks to fire rated doors all the time in the field.

Impeding Egress

A simple impediment to free egress is a deadbolt installed on the same door as an exit device - this is against life safety code in most jurisdictions. If the deadbolt were locked in the event of a fire, panicking people might pile up at the door, injuring themselves as they try to escape. Saying that the deadbolt will be unlocked while occupied is usually not adequate to appease building inspectors.

Preventing people from exiting a space is contrary to life safety code. The purpose of life safety code is to ensure that people can escape in the event of an emergency. There are exceptons, for example, in some jurisdictions jewelers are allowed to lock people in the store with an electric strike or magnetic lock; the door can only be released by one of the jewelry store personnel from behind the counter. This, of course, is to prevent theft. To me, this raises the specter of innocent customers trapped in a locked store with armed thieves, but apparently some inspectors think it's worth the risk, so who am I to disagree?

Access Control

It is usually against life safety code to lock an exit door from both sides in order to create a credential in / credential out system, typically called card in / card out. By "credential" in this case I mean magnetic stripe card, proximity card or proximity token. The purpose of the card in / card out system is to prevent the sharing of credentials. The system accomplishes this by refusing to recognize the credential through exterior readers until it has been presented to an interior reader. Typically the history of credential acceptance events is tied to a time and attendance system, that is, the access control system is also used to track employee hours, making it a powerful tool to encourage good attendance and to discourage the lending of a card to a friend to grant unauthorized access.

A video surveillance system activated by motion sensor at the door can also help discourage unauthorized entry and monitor egress without preventing or impeding it.

A better way to prevent credential sharing is to use a body part as a credential through biometrics. Biometric systems store information such as infrared scans of retina images or fingerprints. Biometrics are the current cutting edge technology of access control.

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