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Thumb latch debate

Discussion in 'Commercial Building Codes' started by cda, Jun 5, 2019.

  1. cda

    cda Sawhorse

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    So on say a second required exit out of an office, can it just have a thumb latch?
     
  2. fatboy

    fatboy Administrator

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    Thumb latch? Like this?

    upload_2019-6-5_11-27-22.png
     
  3. Ty J.

    Ty J. Sawhorse

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    No can do if similar to Fatboy's example.

    A117.1-2009
    309.4 Operation. Operable parts shall be operable with one hand and shall not require tight grasping, pinching, or twisting of the wrist. The force required to activate operable parts shall be 5.0 pounds (22.2 N) maximum.
    EXCEPTION: Gas pump nozzles shall not be required to provide operable parts that have an activating force of 5.0 pounds (22.2 N) maximum.​
     
  4. Inspector Gift

    Inspector Gift Sawhorse - Made in USA

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    I am in agreement with Ty's answer.
     
  5. steveray

    steveray Sawhorse

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    Me too.....
     
  6. cda

    cda Sawhorse

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  7. Ty J.

    Ty J. Sawhorse

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    [​IMG]

    Regarding accessible use, not a hard no, but it does still require a twisting of the wrist. 309.4 (and IBC 1010.1.9.1) could be cited to say no.

    Additionally, if it is within the means of egress...

    1010.1.9.3 Locks and Latches
    Locks and latches shall be permitted to prevent operation of doors where any of the following exist:
    1. Places of detention or restraint.
    2. In buildings in occupancy Group A having an occupant load of 300 or less, Groups B, F, M and S, and in places of religious worship, the main door or doors are permitted to be equipped with key-operated locking devices from the egress side provided:
      1. The locking device is readily distinguishable as locked.
      2. A readily visible durable sign is posted on the egress side on or adjacent to the door stating: THIS DOOR TO REMAIN UNLOCKED WHEN THIS SPACE IS OCCUPIED. The sign shall be in letters 1 inch (25 mm) high on a contrasting background.
      3. The use of the key-operated locking device is revocable by the building official for due cause.
    3. Where egress doors are used in pairs, approved automatic flush bolts shall be permitted to be used, provided that the door leaf having the automatic flush bolts does not have a doorknob or surface-mounted hardware.
    4. Doors from individual dwelling or sleeping units of Group R occupancies having an occupant load of 10 or less are permitted to be equipped with a night latch, dead bolt or security chain, provided such devices are openable from the inside without the use of a key or tool.
    5. Fire doors after the minimum elevated temperature has disabled the unlatching mechanism in accordance with listed fire door test procedures.

    The above section does not seem to be concurrent with your description, therefore a lock would not be permitted at all along the means of egress.
     
  8. Yikes

    Yikes Gold Member

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    1. Operable with one hand does not necessarily mean "operable in a single movement with one hand".
    If a door is allowed by Ch. 10 "means of egress" to have more than one operation/motion to make it open - - then with a deadbolt, one action unlocks it, and it stays unlocked. The second motion is on the door handle itself.

    2. That leaves the question of the action itself is accessible:
    - Tight grasping is not allowed, but loose grasping is theoretically allowed.
    - Keyholes are allowed because the key is not technically part of the door hardware, and so no one know how big or easy the key is to use.

    As to your question, see also: https://idighardware.com/2010/08/accessible-thumbturns/
    "In my opinion, there are thumbturns that can be operated by someone with a disability, as long as the hardware is installed correctly (incorrect installation can cause binding and make the thumbturn difficult to turn). I requested a staff opinion from the ICC, and I was told that if you can operate the thumbturn with the side of your palm, without grasping it with your fingers, it would be considered accessible. I have also heard of code officials using the tip of a pencil to test the accessible operation of a thumbturn.
    Many thumbturns are now designed so that they pivot from the end rather than the center, requiring less leverage to operate. "
    [​IMG]

    For a more official guideline, see: https://www.access-board.gov/guidelines-and-standards/buildings-and-sites/about-the-ada-standards/guide-to-the-ada-standards/chapter-4-entrances,-doors,-and-gates

    Latches and locks with small parts that must be manipulated can be difficult to use and will not comply if pinching is necessary. However, keys and access cards that are not part of the lockset are not required to comply (but those that do not require pinching or turning provide better access). Hardware that does not require simultaneous actions are better, but some types, such as handles with thumb latches are acceptable.

    [​IMG]Recommendations:

    • Specify hardware that is usable with a closed fist of loose grip
    • Bars, pulls, and similar hardware should provide sufficient knuckle clearance (1½” minimum) to facilitate gripping
    • Avoid hardware that requires hand or finger dexterity, fine motor movement, or simultaneous actions.
     
  9. Rick18071

    Rick18071 Sawhorse

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    I was always told that if you can use it without any fingers, just with your palm, it's accessible.
     
    Inspector Gift likes this.
  10. Pcinspector1

    Pcinspector1 Platinum Member

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    [​IMG]

     
    my250r11, MtnArch and Yikes like this.
  11. ADAguy

    ADAguy Sawhorse

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    CH 10 vs CH 11?

    Ch 11 (more restrictive) takes precedence as to access requiring a single action to operate, no?

    ie: RR door with a separate privacy lock (deadbolt) vs an in the lever button (single action to release).
     
  12. JPohling

    JPohling Sawhorse

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    I go with single action.
     
  13. Yikes

    Yikes Gold Member

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    Where in Ch. 11 does it say that accessibility requires a single action to operate a door?
    "Operable with one hand" does NOT mean "operable with a single action".
     
  14. JPohling

    JPohling Sawhorse

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    CBC 1010.1.9.5 Unlatching. The unlatching of any door or leaf shall not require more than one operation.
     
  15. Ty J.

    Ty J. Sawhorse

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    ADA has it backwards; Ch 10 is more restrictive. As per the OP example, a throw bolt and a door handle, even if both are accessible use, is not permitted within the means of egress.

    1010.1.9.5 Unlatching
    The unlatching of any door or leaf shall not require more than one operation.
    Exceptions:
    1. Places of detention or restraint.
    2. Where manually operated bolt locks are permitted by Section 1010.1.9.4.
    3. Doors with automatic flush bolts as permitted by Section 1010.1.9. 3, Item 3.
    4. Doors from individual dwelling units and sleeping units of Group R occupancies as permitted by Section 1010.1.9.3, Item 4.
     
  16. Yikes

    Yikes Gold Member

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    JP and Ty, yes of course that is in Ch. 10, "means of egress". But it is not a Ch. 11 accessibility requirement. And single action is only an egress requirement, not an ingress requirement.
     
  17. conarb

    conarb Sawhorse

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    This has been going on for over 20 years, back in the UBC days I went to my commercial hardware supplier (shop for keying, took locks apart for split finishes etc,) and asked why I wasn't getting an interconnected deadbolt on my front door like the last building? He said different city, some require them and others don't, he reached in his desk drawer and pulled out a list showing the cities statewide that require interconnected deadbolts.
     
  18. ADAguy

    ADAguy Sawhorse

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    "single operation/action" is an ADA criteria and as noted above is also a Chapter 10 requirement, no?
    Users with disabilities come in many flavors, level of cognition being one of them.
    Those with limited cognition can be confused by requiring/allowing multiple operations to open a door.
     
  19. Yikes

    Yikes Gold Member

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    ADAguy, I appreciate what you are describing about helping those with limited cognitive or other abilities. I once had a project where we installed a motorized ped gate opener and proximity sensor + FOB for a man in a wheelchair who had no upper limbs.
    But I think it is important on a code forum, when describing what ADA requires, not to overstate the boundaries of what is allowed.
    I cannot find anywhere in the accessibility codes or regulations were single operation/action is required. (If that were the case, no keyed locks would be allowed by ADA on any manual entry doors or gates.)
    Please provide a specific citation within ADAS where it says that single operation/action is required.

    Per Ty J's post: Ch 10 requires single operation (with exceptions) for exiting / egress. But there is no Ch.10 limitation on the number of operations required for entry.
    In any case, multiple operations, each operation requiring only one hand and without tight grasping or pinching, are allowed by ADA.
     
    Ty J. likes this.
  20. mark handler

    mark handler Sawhorse

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    Cannot grasp it....
     

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