What field modifications to fire-rated doors are allowed to be made?


NFP80 2016 states, The following job site preparations shall be permitted:

  1. Holes for surface-applied hardware, Function holes for Mortise Locks, and holes for labeled Viewers. Drilled hole size not to exceed 1” dia. with the exception of holes for cylinders. Other holes exceeding 1” dia. Shall be permitted for surface applied hardware installed in accordance with the door manufacturer’s listing and the hardware manufacturer’s listing.
  2. Drilling raceways for wires on the job site when permitted by the laboratory with which the door is listed, must also be performed in accordance with the door manufacturer’s listing.
  3. A Maximum of ¾” Undercut on rated wood and composite doors is allowed.

Reference: NFPA80 2016 thru

Note: When performing any permitted Field Preparation / Drilling of rated “mineral core” doors on the job site you must be sure to comply with the NEW OSHA Respirable Crystalline Silica Standard.

  • Notify the Project Supervisor that you will be performing work that will produce dust containing Silica particles.
  • Approved dust collection equipment must be used.

Approved PPE / Respirators must be used.


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