Open fire doorAfter working for almost 40 years in the hardware industry – 30 years with the Allegion brands – and 15 years writing daily posts on iDigHardware, there aren’t a whole lot of things that make me go, “Hmmmm…”    Today’s Quick Question was an exception:

If the permitted mounting height for operable hardware is between 34 inches and 48 inches above the floor, does this range also apply to fire exit hardware?

My first thought was that the codes and standards state this height range requirement without specifically addressing or exempting fire exit hardware, so I didn’t immediately see an objection to installing fire exit hardware as high as 48 inches above the floor or as low as 34 inches above the floor (or as further limited by state or local codes).

But then I pondered the question further.  If fire exit hardware is installed at the manufacturer’s standard mounting height during the fire test, would it function the same way if it was mounted 6 to 8 inches higher or lower?  Maybe, maybe not.

For vertical rod fire exit hardware, changing the location of the device probably wouldn’t be as much of an issue, because the latching positions do not change.  But for mortise and rim devices, the change in mounting height could affect the deformation profile of the door during the fire endurance portion of the test.  There is no way to know without testing the door with the hardware installed at a different mounting height.

My unofficial answer would be that if the installation instructions show the fire exit hardware installed at a specific location (rather than a range), and a different height is desired, the door and hardware manufacturers should be consulted to see if additional testing has been conducted.  If not, it would be up to the authority having jurisdiction (AHJ) to decide whether to allow the alternate mounting height as an equivalency.

Have you had experience with installing fire exit hardware at a mounting height other than the manufacturer’s standard location?  Tell us in the comments!

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