This post was printed in Doors & Hardware
Someone recently asked me why, after going to architectural school, I decided to become a hardware consultant instead of an architect. Right around graduation, I decided that I couldn’t become an architect because the process was way too subjective for me. I like right/wrong, black/white. I like math…you get an answer and it’s right or wrong.
I think that has a lot to do with my interest in the codes. When someone asks me a code question I can usually go right to the applicable code book and translate what is written there, and there’s always the commentary or handbook to give a little extra insight. They’re not always black and white but we can work toward an understanding of the intent even if the language isn’t perfect. The AHJ can sometimes be a bit of a wild card, but they are usually open to having a discussion and most of the time we end up on the same page.
I hate to respond to a question by saying, “Well, that’s a grey area…” In those cases I like to dig around until I can provide a solid interpretation with proof to go along with it. My interpretation isn’t official, but at least it’s something to refer to and discuss.
In my opinion, the issue of electric strikes on fire doors is NOT a grey area, but in researching the requirement for someone who needed some evidence, I discovered that the codes are not very specific about it. You need to put all of the pieces together to provide something more than “because I said so.”
The question has come up several times in relation to electric strikes on stair doors. According to current codes, most stair doors have to allow reentry back into the building during a fire, therefore, a fail safe product must be used. With a fail safe electric strike, cutting the power means that the spring-loaded keeper is the only thing holding the door closed, and that is not enough to be considered positively latched. The pressure from a fire can push the latchbolt right through the keeper and the open door will allow smoke, heat, and gases to compromise the stairwell. I have had several people tell me that the pressure in the stairwell will keep the door latched, but I have never seen a basis for that belief in the codes.
If a door is fire-rated, an electric strike has to be fail secure to provide positive latching. And a fail secure electric strike will not provide for stairwell reentry. So in my opinion, electric strikes should not be used on stair doors, but the fail safe / fail secure question is not specifically addressed in the code language. You have to look at all the evidence and come to a conclusion.
The International Building Code clearly states that stair doors must “be capable of being unlocked simultaneously without unlatching,” and the IBC Commentary further clarifies the latching requirement by stating, “The unlocking of the door must not negate the latching feature, which is essential to the operation of the door as a fire door.“ See below for the code excerpt.
NFPA 80 says: “Electric strikes shall be permitted to be used in lieu of conventional strikes in single swinging doors and pairs of doors where provided for in the published listings.”
I looked at the UL Building Materials Directory to see if the “published listings” would help clear it up, but I didn’t see anything specific regarding fail safe / fail secure (Ref 1, Ref 2). I found a couple of references in a manufacturer’s catalog:
Fail Safe — FS electric strikes require power to be applied to lock the strike lip. On loss of power, the strike is unlocked. Building codes prohibit the use of fail-safe strikes on labeled openings.
UL listed Burglary Resistant CVXY and Electric Strike for fire doors or frames GXAY (fail secure only).
And these Von Duprin fail secure strikes have UL labels for fire and burglary, while the fail safe strikes only have a UL label for burglary:
If you connect the dots, it seems obvious that a fail safe electric strike won’t meet the latching requirements, and a fail secure strike won’t meet the reentry requirements, so electric strikes should not be used on stairwell doors. On other fire-rated doors which are not required to unlock upon fire alarm or a signal from the fire command station, a fail secure electric strike can be used.
Here’s the text from the IBC and Commentary:
Stairway exit doors are permitted to be locked from the side opposite the egress side, provided that they are openable from the egress side and capable of being unlocked simultaneously without unlatching upon a signal from the fire command center, if present, or a signal by emergency personnel from a single location inside the main entrance to the building.
Based on adverse fire experience where occupants have become trapped in smoke-filled stairway enclosures, stairway doors generally must be arranged to permit reentry into the building without the use of any tools, keys or special knowledge or effort. For security reasons, this restriction does not apply to the discharge door from the stairway enclosure to the outside or into an exit passageway (Exception 1). Section 403 for high-rise buildings permits locking doors from the stairway side, provided the doors are capable of being unlocked from a fire command station and there is a communications system within the stairway enclosure that allows contact with the fire command station (Exception 2).
Exception 3, for security reasons, allows the stairway exit door(s) to be locked, preventing ingress from the exit discharge side of the door. In addition, to allow quick entrance for fire fighters and emergency responders, a means of simultaneously unlocking all of the doors by emergency personnel must be provided. This provision further requires that the stairway doors be unlocked without unlatching. Stairway doors will typically be fire door assemblies, and their continued latching is necessary to maintain the integrity of the fire-resistive separation for the exit enclosure. The remote unlocking signal shall be initiated from the fire command center, if provided, or a single point of signal initiation at an approved location inside the building’s main entrance.