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Apr 02 2009

Glass Doors with Electric Strikes

Category: Glass,VideosLori @ 2:24 pm Comments (10)

I’m currently working on several projects that have glass doors in walls that are acting as 1-hour fire barriers with closely-spaced sprinkler heads above the glass.  The problem with this application from a hardware standpoint is that the Blumcraft, CR Laurence, and Dorma Glas panic hardware that is typically used on glass doors does not have active trim (like a lever handle) to retract the latch from the secure side.  To unlock these doors, you would typically use the dogging feature of the panic device to leave the doors in a push/pull condition, but because they require positive latching, dogging is not an option.  I have searched the world over for a solution to this problem, but the only possibility I’ve found so far is using fail secure electric strikes to release the latches.  Unfortunately, this application is extremely noisy, as illustrated by the video below.  If anyone has any ideas, I’d love to hear from you.

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10 Responses to “Glass Doors with Electric Strikes”

  1. Jess says:

    hello Lori, i hear a click before the door latches (about 4 inches from door shut) since to me this installation appears to have floor closers, sounds to me like the arm mounted in bottom edge of door is loose in door or on closer’s spindle.

    to fix this, there should be a screw on side of door (inside or edge of door at bottom, if closer selected has what is called end loading arm) to tighten arm to closer shaft. if that doesn’t fix it, then its possible that the arm itself is loose in bottom rail of door and to fix that you have to turn the screw until both screws (depends on brand of closer used, such as Rixson) are tight on both EXT and INT side of door (center arm in door basically)

    hope my suggestion helps,

  2. Tom Colton says:

    Hello Lori, The noise made as the door swings out is most likely caused by the latch bolt at the being incorrectly adjusted. It seems that it is being pushed into the panic tube and then snapping back up once it clears. Adjusting the latch bolt lower so it clears the keeper when the panic bar is depressed should eliminate the opening noise. I also think that the rubber bumper pads are missing from the ends of the stop screws.

  3. Andy says:

    Hi all – I’m just wondering if, in the time between 2009 and 2013, anyone has come up with a cheaper option than electric strikes to solve the problem at the top of this thread? (all-glass doors that require positive latching and therefore cannot use dogging on the panic device to allow access from the pull side). Any ideas are appreciated – thanks!

    • Lori says:

      Hi Andy –

      I haven’t heard of any new ideas or products for this…it would definitely have to be an electrified product so I don’t think it will get much less expensive than an electric strike. The issue for me is the noise more than the cost.

      – Lori

  4. Joe says:

    Hi Lori,
    Do you know if this option would be acceptable under NFPA 101? I believe glass, if properly gasketed to prevent the passage of smoke, is permitted as a smoke barrier if closely-spaced sprinklers are installed. I am not certain that these glass doors can serve within a smoke-barrier, unless they are gasketed and latching. This is a very clever solution for the latching aspect. Please let me know your thoughts on whether this application would need to be gasketed in a smoke-barrier assembly.

    • Lori says:

      Hi Joe –

      As far as I know, it applies only to atrium applications. Here is the section from NFPA 101-2012 (you’d have to check the specific occupancy chapter to make sure it is not prohibited):

      8.6.7* Atriums. Unless prohibited by Chapters 11 through 43, an atrium shall be permitted, provided that the following conditions are met:
      (1) The atrium is separated from the adjacent spaces by firebarriers with not less than a 1-hour fire resistance rating, with opening protectives for corridor walls, unless one ofthe following is met:
      (a) The requirement of 8.6.7(1) shall not apply to existing, previously approved atriums.
      (b) Any number of levels of the building shall be permitted to open directly to the atrium without enclosure,based on the results of the engineering analysis required in 8.6.7(5).
      (c)*Glass walls and inoperable windows shall be permitted in lieu of the fire barriers where all the followingare met:
      i. Automatic sprinklers are spaced along bothsides of the glass wall and the inoperable windows at intervals not to exceed 6 ft (1830 mm).
      ii. The automatic sprinklers specified in 8.6.7(1)(c)(i) are located at a distance from the glass wall not to exceed 12 in. (305 mm) and arranged so that the entire surface of the glass is wet upon operation of the sprinklers.
      iii. The glass wall is of tempered, wired, or laminated glass held in place by a gasket system that allows the glass framing system to deflect without breaking (loading) the glass before the sprinklers operate.
      iv. The automatic sprinklers required by 8.6.7(1)(c)(i) are not required on the atrium side of the glass wall and the inoperable window where there is no walkway or other floor area onthe atrium side above the main floor level.
      v. Doors in the glass walls are of glass or other material that resists the passage of smoke.
      vi. Doors in the glass walls are self-closing or automatic-closing upon detection of smoke.
      vii. The glass is continuous vertically, without horizontal mullions, window treatments, or otherobstructions that would interfere with the wetting of the entire glass surface.
      (2) Access to exits is permitted to be within the atrium, and exit discharge in accordance with 7.7.2 is permitted to be within the atrium.
      (3) The occupancy within the atrium meets the specifications for classification as low or ordinary hazard contents. (See 6.2.2.)
      (4) The entire building is protected throughout by an approved, supervised automatic sprinkler system in accordance with Section 9.7.
      (5)*For other than existing, previously approved atriums, an engineering analysis is performed that demonstrates that the building is designed to keep the smoke layer interface above the highest unprotected opening to adjoining spaces, or 6 ft (1830 mm) above the highest floor level of exit access opento the atrium, for a period equal to 1.5 times the calculated egress time or 20 minutes, whichever is greater.
      (6)*In other than existing, previously approved atriums, where an engineered smoke control system is installed tomeet the requirements of 8.6.7(5), the system is independently activated by each of the following:
      (a) Required automatic sprinkler system
      (b) Manual controls that are readily accessible to the fire department

  5. Michel says:

    I am looking for 22MM Glass Door Patch fitting. Can anyone help?.

    • Lori says:

      Hi Michel –

      I’m sorry – I don’t do much work with glass doors so I’m not sure where to get patch fittings.

      – Lori

  6. RANDALL OXLEY says:

    Hi Lori,
    Am I addressing Lori Greene at Allegion? I have made an electric strike for these Blumcraft devices. It is a surface mounted device, and it’s been in service for 10 years or so. I understand the noise issue, and it’s greatly amplified by the glass door and structure! I think I can introduce some sound-proofing elements that would help- at least with the sound of the keepers slapping back to the locked position, and the roller latch pushing back into the strike. Let me know if you’d like to see what I’ve done, and I’ll come by with it.
    Randy Oxley

    • Lori says:

      Hi Randy!

      Yes, it’s me! Remember when I came to your shop about 11 or 12 years ago? I loved the strike modification you made, but the architect for the project I was working on went with the standard strike. A few years ago he called to see if anything new had been introduced because the museum was complaining about the noise from the strikes. I gave him your name – I don’t know why they didn’t at least try it out.

      – Lori

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