This is a really interesting question and I’ve love your insight on it. One of the disadvantages of electromagnetic locks is that when power is cut to the mag-lock the door is not locked, which creates an obvious security problem during a power failure. Imagine an existing door with a mag-lock that is released by a sensor when a building occupant approaches the door. The mag-lock is also released by an auxiliary push button, activation of the fire alarm, and power failure, as required by the model codes. Is it code-compliant to add a deadbolt to a door with a mag-lock, that can be used to lock the door during a power failure?
My initial reaction was that you can’t add a deadbolt because it would be a second lock, and the codes require the door to unlatch with one operation. BUT – mag-locks are often installed on doors with latching hardware – like a lockset/latchset or panic hardware, and the sensor unlocks the mag-lock without any releasing operations performed by the building occupant. The IBC specifically says that you can have a mag-lock and panic hardware on the same door as long as the mag-lock is released either by a sensor or by a switch in the panic, so that sets a precedent for allowing the mag-lock and another piece of locking/latching hardware.
Even if the deadbolt was engaged while the mag-lock was powered, a building occupant would only have to perform one releasing operation to unlatch the door (turn the thumbturn). If the sensor was not working and the auxiliary push button had to be used, it still wouldn’t be any different from someone pushing the auxiliary push button and then turning a lever or pushing on the touchpad of a panic device. One disadvantage is that the deadbolt could mechanically lock the door and override the access control system, but that’s not a code issue.
What do you think? If the mag-lock meets all of the code requirements for electrified locks released by a sensor, and the deadbolt meets all of the code requirements for mechanical hardware, can they be installed on the same door? WWYD?
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“”If the sensor was not working and the auxiliary push button had to be used, it still wouldn’t be any different from someone pushing the auxiliary push button and then turning a lever or pushing on the touchpad of a panic device. ””””
Two operations??!
I am thinking dead bolt allowed where the code allows it, but at any time
One operation to open the door
Hi Charles –
Normally you would walk up to the door and the mag-lock would unlock without you needing to do anything. So turning the thumbturn for the deadbolt would be the one operation. And if the auxiliary button needs to be used because the sensor is malfunctioning (not common), pushing the button and then turning the thumbturn isn’t much different from pushing the button and turning a lever or pushing on a panic.
– Lori
Agreed – that’s how I read it. Two operations?
Does the door need barrier-free operation? Would “pinching” of the thumbturn be necessary to operate it?
Hi Joel –
Many thumbturns are operable without tight grasping, pinching, or twisting of the wrist…usually the thumbturn is somewhat elongated and pivots from the end rather than the center.
– Lori
I would be curious what the building type is. I have hospital facilities to take care of, dead bolts are prohibited. In a couple of areas like our Behavioral Health, I have the mag lock on emergency power with a battery back up to keep it lock during the 8 seconds before the Generator kicks in. Because the majority of our doors has to latch we use either mortise locks or cylindrical ADA.
Hi Terry –
It is a business occupancy (office).
– Lori
One alternate option to adding a deadbolt is providing a battery backup at mag-lock doors for use when there’s a concern about short term power interruption. I think that the dead bolt is compliant if the staff is trained to use it only used when the mag-lock is inoperative. Perhaps a switch could be used that would deactivate the mag-lock when the deadbolt is locked.
Hi Eric –
Battery back-up on mag-locks can be problematic, because the model codes require electrified locks released by a sensor to also unlock upon loss of power. I have seen back-up power allowed on mag-locks if the back-up power also controls the fire alarm system, but I wouldn’t recommend using separate batteries in the power supply for the mag-locks.
– Lori
Lori,
Where does the deadbolt fall into ADA requirements?
The deadbolt requires a twisting motion with the users fingers. Typically deadbolts are installed 48″ or 60″ off the floor as well.
Hi Chad –
There are quite a few thumbturns that are operable without tight grasping, pinching, or twisting of the wrist. The model codes and standards require releasing hardware to be mounted between 34-48 inches above the floor (34-44 inches in CA), so the deadbolt would have to be mounted in that range.
– Lori
Pretty limited use case. The occupancy has to allow the use of a deadlock and the inside operation has to be thumbturn, not keyed.
As to single motion egress you’re right if the approach sensor or touchpad release operate but in the event that they are not operative, two locking devices are encountered and now you have a safety violation at the worst possible time.
A battery backed power supply is probably less expensive than the additional lock and adheres to the principle of single motion egress.
I would be hard pressed to use a mechanical deadlock in this instance.
Hi John –
There are some locations where a double-cylinder deadbolt could be used (https://idighardware.com/2014/04/decoded-key-operated-locks-june-2014/), but these are interior doors in an office building so they would be thumbturn deadbolts. As long as it’s a door that does not require panic hardware (these are actually inswinging doors), the occupancy chapters would not prohibit a deadbolt that meets the operational requirements of the codes.
If the sensor failed and the auxiliary push button was used to release the mag-lock, a second operation would be needed to retract the deadbolt. But this is basically the same as using the auxiliary push button and then turning a lever or pushing on the touchpad of a panic device.
Most AHJs don’t allow battery backup for mag-locks because the codes require the doors to unlock upon power failure. I usually recommend back-up power for mag-locks only if it’s the same back-up system that powers the fire alarm system. I base this on the National Electrical Code.
– Lori
As always: it depends on the occupancy and when the deadbolt can be used.
If the occupancy is M, or another one that allows deadbolts when building is un-occupied, then by all means. A door to a store or resturant, that has a mag that is controlled by an access control system, can have a double cylinder deadbolt for final lock down. Must meet the signage requirement “this door to remain unlocked while building is occupied” in 1″ letters.
Hi Glenn –
I agree with you on the double-cylinder deadbolt, but these are interior doors in an office building so the deadbolts would have a thumbturn on the egress side. The codes do not prohibit this as long as the deadbolt meets the requirements – one operation to unlatch the door, releasing hardware between 34-48 inches AFF (34-44 inches in CA), no tight grasping/pinching/twisting, etc.
– Lori
I may be missing something, but…. Why would you install a deadbolt on a door with a maglock? If the goal is to secure the door in the event of a power failure, wouldn’t locking cylindrical/mortise/panic hardware achieve the same result? Unless the customer/owner is of the mindset “with standard locking hardware it’s hard for me to tell/know if the maglock is working correctly”, the deadbolt method is either cost savings or a mechanical override approach to another issue non-relating to door hardware. In short, I think it could meet code (AHJ approval pending).
Hi Keith –
I think the reason the building owner asked about a deadbolt is because he does not want latching hardware on the doors, and the deadbolt would only be used on rare occasions.
– Lori
As I hit submit on my previous post, I realized an electric strike or electric unlocking door hardware maybe required to allow ingress with the described setup.
On a fire door – maglock+motion sensor/activation floor mat+latch set OR maglock+latchset with in-built Request to exit switch.
On non fire rated door – maglock+motion sensor/activation floor mat+push/pull.
I consider any other hardware (including push button) a ‘second and knowledgable action’ which violates codes
Is it possible to provide a maglock and store room function lock on the same door
Yes it would be physically possible, as long as the door still allows code-compliant egress, but you would need to be able to unlock both locks from the outside for access. This would not be my first choice from the aspect of functionality.
– Lori