The instructors in my Fire Door Assembly Inspector (FDAI) class showed us a really handy gauge to measure clearances around fire rated doors, and since I’m going to do my first *official* inspection tomorrow I tracked one down. It can easily and accurately measure 1/16″, 1/8″, 3/16″, 1/4″, and 3/8″ gaps, and a 3/4″ undercut. For only $18.95, you can be the proud owner of your own Door Gap Gauge by shopping online at doorgapgauge.com.
For those of you who are wondering why anyone would ever want to measure their door gaps, NFPA 80 limits clearances for fire rated doors to the following:
- Wood Doors – 1/8″ at head, jambs, and meeting stiles of pairs, 3/4″ at sill
- Hollow Metal Doors – 1/16″ – 3/16″ at head, jambs, and meeting stiles of pairs, 3/4″ at sill
Note: I am not in any way affiliated with doorgapgauge.com.