This post was published 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.
Commentary:
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.
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My first response to this post is, “Why would anybody argue this?” 🙂 You must have a lot of patience.
I would like to present a scenario that will spark some thought as to why you may want electric strikes on stairwell fire doors.
Electrified mortise locks (fail safe) were originally installed on the stairwell doors for security purposes (homeless or other tenants accessing other tenant floors).
I have a tenant that occupies complete multiple floors and would like their employees to be able to use the stairwell to go from floor to floor. This is not possible with the current situation.
So, if the tenant installs their own card reader system so they can monitor activity, electric strike that fails secure on our fire alarm signal I see no problem with this.
In a fire alarm situation our mortise locks fail safe and the tenant electric strikes fail secure, therefore, providing the POSITIVE LATCH required by code.
Hi Ron –
I have had a few applications during my career where a fail secure electric strike was used on a stairwell door that was also equipped with a fail safe lock. One application that comes to mind is a stairwell door with an automatic operator. It is acceptable by code to use a fail secure electric strike on a fire door, but since it won’t meet the requirements for stairwell reentry, the fail safe lock or fire exit hardware trim would also be required for stair doors.
– Lori
Thank you!
Hi Lori,
Some confusion, or should I say the demand for “electric strikes” on stairwell doors might be coming from a small misunderstanding of correct terminology. There are a couple of products out there specifically designed for this exact application. For example, the Architectural Control Systems Inc. “Gemini Locking System” is a UL listed locking system that combines a special mortise lock modification along with a special strike, UL tested and listed together, allowing a fail safe electrical operation while maintaining the proper latching requirements for labeled stairwell doors. The strike is referred to as an “operator”, even though it looks a lot like the more common electric strikes used today for access control applications. The Gemini Operator works in unison with the mortise lockset. All of the power is run to the door frame and into the operator, no power transfers or raceways through the door to the mortise lock are required. The voltage capabilities for the frame mounted operator are designed to integrate well with the life safety systems already in place in any building occupancy, they range from 115AC, 24Vac/dc, 12Vac/dc, or pneumatic operation. Here’s a link to a PDF diagram and description of the system I just explained: http://acsi-inc.com/cms/uploaded/docs/8500%20GEMINI.pdf
I hope this helps,
Hal
The evidence seems obvious to me too. According to the code, the door has to be latched so it doesn’t matter if it’s true that pressure will keep a door shut or not. It still must be latched. No gray area there.
So just use a fail safe electrified lock (or exit device) – simple…except in the case of retrofit applications, or the “fear” of using something besides an electric strike (God forbid).
Why not just use an electric lock such as the Schlage ND80PDEL. This unlocks when power is cut off. Unless you are using it with an auto operator, which I assume you would not be doing in a stairwell door.
Very informative – Thanks
Electric mortise are the fad where I am at. Both rated fire doors and non rated fire doors.
thank you for info.
in using fail secure locks for electrical or mechanical rooms, what will happen if a person trapped in the room and fire alarm activate the lock of the door?
or in case of power cut and fire happened in the room.
In most cases, fail-secure and fail-safe locks and strikes allow free egress at all times, regardless of whether there is power or not.
– Lori
I have an architect that claims they have permission from the AHJ to use fail-safe strikes on this 3 story building as long as they have a door closer on the door. This seems like a problem.
I have never heard of an AHJ allowing that and I would not supply fail safe electric strikes for fire door assemblies, as they are not listed to UL 10C.
– Lori
I have a scenario. i have been a locksmith for 30 years and our general thought and guideline is that we do not do electric strikes on fire rated openings. We us electrified cylindrical, mortise or electrified exit device trim. This is a unique situation. If someone can give me a more concrete answer than what i read.
In the lobby of a 4 story office building. I have a door that leads to the parking garage. On the lobby side i have a card reader that activates the electrified mortise lock that is also controlled by an exit device from the garage. Exit device allows free egress. Simple right? Here is the problem i have. The owner had an automatic door operator installed. This will only work if you push on the exit device and then push the button or use your key fob from the lobby side, turn the handle to retract the latch then push the button. Not cool for anyone in need of using it. In my determination from reading several publications and codes, the thought is that i can use a fail secure electric strike that release when the button is pressed from the garage side. Causing the door to be “unlocked” so it can open with the auto operator. Lobby side, present key fob, unlocks the mortise trim and when button is pushed unlocks strike and allows door to open. So, if this is not a stairway door i should be able to install the fire rated strike to allow for the operation of the automatic operator?
Hi Michael –
A fail secure electric strike would be code-compliant…the only issue is that NFPA 80 limits the job-site preps to round holes. If the strike requires a rectangular face cutout, you may have to go through the process to get the field modification approved by the listing lab, or have the frame relabeled in the field. Another option might be to add electric latch retraction to the fire exit hardware.
– Lori