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Corridor Door - Gaps

What is the minimum gap requirement for smoke resistant corridor doors?

Any examples are for illustrative purposes only.

The Joint Commission allows gaps which do not exceed 1/8 inch for the meeting edges of door pairs as a compliant smoke resistant corridor door. The door undercut is not to exceed 1 inch. Gaskets may be used to reduce or close the gap and can also be used if the door is not a fire rated door.  

Note that the Life Safety Code NFPA 101-2012: 18/ only requires that the door is smoke resistant.  The 1/8 inch gap criteria has been adapted by The Joint Commission to provide an objective measurement for uniform and consistent survey results.  

Additional Resources:
NFPA 101 – 2012: 18/
Last updated on March 29, 2021
Manual: Behavioral Health
Chapter: Life Safety LS

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