Printed from the blog of Lori Greene, AHC/CDC, CCPR, FDAI
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Aug 04 2015

WWYD? Mortise to Cylindrical Conversion

Category: Fire Doors,Locks & Keys,WWYD?Lori @ 9:35 am Comments (18)

Mortise to Cylindrical ConversionI’ve had many requests for help lately with regard to converting an existing fire door with a mortise lock to a cylindrical lock.  There are several concerns here:

a) Preparing the door for the 2 1/8-inch-diameter hole, which is larger than what is allowed as a job-site preparation by NFPA 80.  This may be allowed as a field modification by the listing laboratories with prior approval.

b) Filling the existing mortise pocket to maintain the integrity of the door.  This is especially problematic on wood doors.  I have witnessed several wood door fire tests and I believe this void would cause the door to fail.

c) Covering existing holes from the mortise lock.  There are conversion kits available which cover the face holes and fill the 86 edge (scalp plate cutout), but I don’t know of any that have been listed for use on a fire door.

So I ask you, readers of iDigHardware…what would you do?  Do you know of an acceptable method for making this conversion on a fire door?

Thank you to Nolan Thrope of Allegion for the photo!

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18 Responses to “WWYD? Mortise to Cylindrical Conversion”

  1. Rich says:

    Years ago, we used to do just like this picture. Now we say … Buy a door and meet code. Quite similar to converting the Sargent 7600 integra lock. We have a similar problem with stairwell doors in old buildings that are cylindrical and should be upgraded to exit devices. They have an asbestos layer in them and we keep saying “buy doors”. Not funded yet so no upgrades. In a magical world, there would be enough $$$ to fix this stuff but we would need more locksmiths to do it.

  2. Debbie Purcell, AHC says:

    As an owner of a distributorship I would not want to assume the liability of putting something out there that I am not 100% sure can meet the fire code. This is a litigious world these days.

  3. Dave Snell, AHC says:

    My first question is why would you swap a mortise lock for a cylindrical lock. This application stills calls for a Grade 1 lock and price difference between the two is not that much different. Of course if you have a “cheap” building owner this can happen but as a distributor I would not recommend it.

    • Ron Richter says:

      this pic does actually appear to use a grade 1 cylindrical lever. for a retrofit, it does look nice. of course, voiding any existing ‘fire label’ not withstanding..

  4. Jim Elder says:

    Is the door shown in the photo rated? Anyway, I am with Debbie on this one, but I speak only from a consultant’s perspective (of course as a consultant, I would not use cylindrical locks on something I wanted to secure). Why not just change out the mortise lock? The only reason I can see is that the owner may have been reclaimed from somewhere else.

    Debbie. What would your company charge to replace this door with one that matches the finish? Matter of fact I open that question to all door folks.

  5. David R. DeFilippo says:

    First , it’s a dumb idea , and I would nicely try to explain that. Why go backwards in quality. Second I don’t think the assumed liability is worth it.

  6. Tom Breese says:

    Plan A: replace the lockset in-kind. Plan B: get a labeling agency field inspection agent to witness this massive modification, see if that individual would be willing to ‘sign off’ and apply an auxiliary label. Plan C of course: replace the door.
    I agree, I think that the door in your photo would burn through around the lockset, unless perhaps the Fire Door Caulk product from Fire Door Solutions could be packed into the cavity(?). Too bad the costs of testing are so high, it would be interesting to see how this sort of modification holds up in a furnace test.

  7. Curt Norton, CSI CCS says:

    I would recommend a mortise lock replacement. Why save a few bucks on the lock to a) do all that extra work or b) take on a whole lot of liability and risk life safety? With the extra labor, is it really cheaper to use a kit with a cylindrical lock?

  8. Vince Black says:

    We would not do this on a fire door in a rated opening.
    Buy a new door.
    Way too much liability.

  9. Khozema Kazi, AHC, FDAI says:

    Fill the entire motise cavity (face and edge) with saw dust and glue mix. After it solidifies, make new cylindrical lock prep. Get opinion on this method from labeling agency or have it inspected by labeling agency field inspector, for approval.

    • Ron Richter says:

      yeah, for a truck roll, (field service call), a credentialed tech from a credentialed agency can apply a $5.00 label and charge you a $1300.00 fee. that is of course, if he is comfortable putting his and his companies’ financial solvency in potential harms way..

  10. Charly Shannon says:

    I have seen this done to install a combo lock.

  11. Chuck Noble says:

    This is done a lot in field, mostly in the hotel industry where a new card lock has an over sized bore and is permitted to be field modified by the locks’ manufacturer, as tested.

    There are a lot of issues with this.

    I have witnessed a few fire tests and have seen first hand how vulnerable a fire door is in a fire condition. The door cannot withstand a fire condition with a vacated mortise pocket. The mortise pocket surroundings gets blown out with the hose stream even with a mortise lock in place. The mortise lock housing takes on the fire protection, saving the door from blow out. If you covered the pocket with a steel plate most likely the plate would be blown off by the hose stream or the plate would fall off due to positive pressure conditions inside the furnace and would burn off.

    Remember how small the screws are that attach these plates and are they steel? Side note: Aluminum melts away at 900 degrees, less than 10 minutes into a fire test.

    Within 5 minutes the entire veneer is gone and only the bare mineral core is protecting the opening along with the mortise lock housing and its latch. Now figure positive pressure at 1500 plus degrees for 90 minutes and then a water hose stream at a minimum of 30LBS of pressure from 20 feet away.

    We will be testing a few more fire door assemblies in the near future. These doors will be tested not for new products but to either confirm or deny some of these types of questions. My guess is to confirm and am willing to put my money on it.

    In the inspection business we need EVIDENCE that a product will withstand a fire condition. We need to look deeper into the code, into the manufacturers’ instructions and their Listing.

    Also, these doors need to be field labeled or re-certified to verify that the door can withstand a fire condition (evidence). The only way that these fire doors can be field labeled is to have a sample door and burn it!

    • Lori says:

      Thanks for sharing your insight, Chuck!

    • Ron Richter says:

      chuck, perhaps i’m not reading your first sentence correctly, but to me it reads something like this? the door is further modified with more holes, and the “lock manufacturer” is “permitting” this? where is the door manufacturer/door shop in this ? is the lock manufacturer going to stand behind the apparently now-voided (as door was supplied to door installer) fire label ? (now standing in the door manufacturers shoes for liability purposes? sorry, i’m asking the questions regarding the statement..

  12. Brendan says:

    I was on a project yesterday with about 60 of these that we are now going back to mortise with full escutcheon trim…. Go Ahead Beat Me Up

  13. Michael Dalrymple says:

    I see a few comments asking why anyone would want to go from the security of a mortise lock to a cylindrical lock….the simple answer is that there are some situations where the solution that the end user is looking for may not be available in a mortise configuration. This has come up recently with some electronic locks.

  14. Sandro Abballe, FDAI says:

    In my limited experience I would say that the only way to resolve this problem is to advise the door manufacturer about the proposed alteration and to make sure that their door would be able to withstand a fire with the new components installed. If such a combination has not yet been tested the opening will need to be field labelled.

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