I was contacted last week by a door and hardware distributor who provided fire door assemblies for a hospital project, with hollow metal frames and wood doors.  Because of the enforcement of annual fire door inspections by CMS and the Joint Commission, facility personnel are focusing more intently on the initial installation of the fire door assemblies to ensure that they are code-compliant from the start.

Clearances around fire doors have always been a pain point – particularly for wood doors (now wood doors rated for more than 20 minutes) where the clearance is limited by NFPA 80 to 1/8-inch at the head, jambs, and meeting stiles.  With manufacturing tolerances and installation variations, it’s difficult to maintain the 1/8-inch clearance, and when there is a clearance problem, there isn’t an easy solution.

If you have experience with how to address excessive clearance, I’d love to hear about it, but my specific question is about measuring the clearance.  On the project in question, a gauge was used to measure the clearance – here’s an example of a door gap gauge although I don’t know if this is the brand that was used.  The 1/8-inch side of the gauge was able to slide “easily” between the door and frame, but the 3/16-inch side of the gauge would not fit.  So the clearance in some areas is slightly over 1/8-inch but less than 3/16-inch.  Is this acceptable, or is it a deficiency?

One thing to note is that there was a change in NFPA 80-2016 that will help in some applications.  The 2016 and 2019 editions allow 20-minute wood and laminate doors in hollow metal frames to have clearance of 1/8-inch +/- 1/16-inch, so the situation described above would be compliant with those editions.

WWYD?  What’s the correct way to measure the clearance?  And what’s the resolution when the clearance does not comply with NFPA 80?

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