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Why don't we like thumb turns?

1008.1.9.5 Unlatching. The unlatching of any door or leaf shall not require more than one operation.

If you have a thumb turn lock and it is in the locked position then it takes more than one operation to open the door

The code permits a "keyed" lock in certain occupancies with the understanding management will have the door unlocked when occupied.

A thumb turn or a keyed lock functions as a latching device. Because a thumb bolt can be locked by anyone it could hinder the unlatching of the door and therefore some do not believe they are code compliant on an egress door even if they do meet ADA requirements.
 
Not sure I agree with the premis that a thumb turn bolt makes it more than one operation to unlatch a door. The code says "the unlatching" shall not require more than one operation. Unlatching and opening are two distinct things. Just like an EEO window, the lock only allows one operation, opening the window is not included in that operation. By the standard you present, in the case of a door, any locking mechanism short of a panic bar, paddle handle or similar would not be allowed.

I guess I am too dense to get this. I know I am in the extreme minority here (maybe alone) but I still fail to see the logic in the blanket of not allowing thumb turns, at least an accessible thumb turn, being thrown on this subject by so many jurisdictions. If you take accessibility out of the equation, it would seem a thumb turn is the safer alternative to a key because even though anyone can lock it, anyone can unlock it. So if someone with bad intentions or a kid messing around turns the lock, they can't break the key off or throw it away or jam an object into it like they could with a thumb turn. I completely understand the notion to allow a key in certain conditions, but not REQUIRE it.
 
The keyed lock is not a requirement it is PERMITTED in certain uses and under certain conditions.

If a door has a door latching device and a separate locking device each device is acting as a latching device.

Look at newer hotels that have a thumb turn on the interior of the sleeping rooms. It takes one operation of the door handle and the thumb turn lock and the latching device are disengaged during the same single motion.

I am not tying to be argumentative just pointing out a different perspective. Ultimately it is what you and the FD can agree upon in your jurisdiction. Just be consistent with application and enforcement.

We allow the thumb turn on single exit occupancies only.
 
First, I don't think anyone is being argumentative, as I am not. I am really just engaging in some theoretical & critical thinking, trying to understand why most places frown on thumb turns when it seems somewhat counter-intuitive. These are the kind of threads I like, you can seldom learn anything if you all agree on something right?

I am all on board with the multiple action part. What I commonly see are single exit occupancies or ones with non-compliant rear exits that aren't counted. We require keyed locks with indicators and signage and that is where I start to stray. I don't see the requirement part of it.....unless it is an accessibility issue. Now I have been informed of the view that most if not all do not view keys as subject to the accessible aspect and thumb turns are.

So what I am finding are two major reasons why some don't like thumb turns:

1) thumb turns are subject to tampering, and

2) Thumb turns are subject to accessibility codes and keys are not.

I am not here to argue those interpretations, though I guess I don't fully understand or agree with them. I just wanted to get to the bottom of why. I am not trying to change anybodys mind, really looking to see if my mind needed changing.

Either way, great conversation.
 
Thumb turns are great in some situations, and can be made accessible. The problem is that anybody can lock the door with a thumbturn while the building is occupied. If the thumbturn is on the bottom stile, somebody would have to bend down to unlock it. This wouldn't be a problem if only a few people were in the building, but in a crowded building the person unlocking the thumbturn would probably get trampled.

It's a shame that we have to think about stuff like this, but trying to stay a step ahead of a few crazy people makes life harder for everybody else.
 
JBI said:
Approved would be as defined in the Code... 'Acceptable to the Building Official'.
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To clarify my statement in reference to this thread is in accordance with section 104.1; shall not be less than what is specified in the code. What is acceptable to the AHJ in accordance with the definition of Approved to my knowlegde would refer to sections 104.10 & 104.11
 
If a door has a deadbolt with a thumbturn, and the deadbolt is the only method of locking/latching the door, and the thumbturn is elongated and able to be pushed back and forth with the side of your palm, and it is mounted between 34" and 48" above the floor, is it acceptable for use on a door in a means of egress and a door on an accessible route? If no, why not?

I am not asking about a fire door (which requires an active latchbolt), or the exception for a key-operated lock, or a door that requires panic hardware.

Here's a photo of what I'm describing: http://www.idighardware.com/wordpress/wp-content/uploads/2009/11/img_4271.jpg
 
mtlogcabin said:
The keyed lock is not a requirement it is PERMITTED in certain uses and under certain conditions.If a door has a door latching device and a separate locking device each device is acting as a latching device.

Look at newer hotels that have a thumb turn on the interior of the sleeping rooms. It takes one operation of the door handle and the thumb turn lock and the latching device are disengaged during the same single motion.

I am not tying to be argumentative just pointing out a different perspective. Ultimately it is what you and the FD can agree upon in your jurisdiction. Just be consistent with application and enforcement.

We allow the thumb turn on single exit occupancies only.
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So what are you seeing on a 2nd exit where panic hardware is not required

And where security of the door is wanted
 
and the deadbolt is the only method of locking/latching the door, and the thumbturn is elongated and able to be pushed back and forth with the side of your palm, and it is mounted between 34" and 48" above the floor, is it acceptable for use on a door in a means of egress and a door on an accessible route?
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Leave it to the door Lady to simplify and clarify.

Yes it is acceptable
 
cda said:
So what are you seeing on a 2nd exit where panic hardware is not requiredAnd where security of the door is wanted
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You could have a mortise lock incorporating a latchbolt and a deadbolt - added security but only one operation to unlatch.
 
So what are you seeing on a 2nd exit where panic hardware is not required
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I will have to get back to you. I can't recall a new project in the last 2 years that haven't been panic or delayed egress on the other doors. We have been blessed with quite a few larger M, A, I and E occupancy projects over the last 3 years.
 
So if a 2nd exit was required

and an ada thumblatch was approved

would you require the door to be unlocked when the building is occupied or would the "one action" of turning the thumb latch satisfy you???
 
cda said:
So if a 2nd exit was required and an ada thumblatch was approved

would you require the door to be unlocked when the building is occupied or would the "one action" of turning the thumb latch satisfy you???
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On a door that requires panic hardware I wouldn't accept a thumbturn, except where a key-operated lock is allowed I think a classroom function deadbolt (thumbturn retracts bolt but does not project it) meets the intent. But if panic hardware is not required, and a door (regardless of the location) had a deadbolt with an accessible thumbturn, mounted in the acceptable range, and no other latching hardware, on what grounds would you reject it? I don't see a problem with this application as long as the location doesn't require a panic.

Speaking hypothetically of course, since I am powerless.
 
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