Commercial Building Inspector B2General Administration, Permits, and PlansHard

A commercial building inspector is reviewing plans for the replacement of a non-fire-rated door in a 1-hour fire-resistance-rated corridor in a 3-story Group B office building. The new door will be a fire door assembly. Which of the following statements regarding the fire protection rating of the new door is correct?

  1. AA 20-minute fire protection rated door is permitted if equipped with a self-closing device.
  2. BA 45-minute fire protection rated door is required, with or without a self-closing device.
  3. CNo fire protection rated door is required if the building has an automatic sprinkler system throughout.
  4. DA 60-minute fire protection rated door is required for 1-hour fire-resistance-rated corridors.
Show answer & explanation

Correct answer: A. A 20-minute fire protection rated door is permitted if equipped with a self-closing device.

According to IBC Table 716.1.1(1), for an opening in a 1-hour fire-resistance-rated corridor wall, a 20-minute fire protection rated door is permitted. IBC 716.5.9 requires fire doors in exit access corridors to be self-closing or automatic-closing.

Why the other options are wrong

  • B. A 45-minute rating is typically for 1-hour fire barriers or shafts, not standard corridor walls.
  • C. Even with sprinklers, fire-rated doors are often required in fire-resistance-rated corridors to compartmentalize smoke and fire, although specific exceptions exist, 'no rating required' is generally incorrect for a fire-rated corridor.
  • D. A 60-minute rating is usually for 2-hour fire barriers or shafts.

Corridor Fire Door Rating (1-Hour Wall)

The minimum fire protection rating required for a door assembly in a 1-hour fire-resistance-rated corridor wall in a Group B office building.

  • Governed by IBC Chapter 7, Fire and Smoke Protection Features.
  • Specific ratings depend on the fire-resistance rating of the wall and location.
  • Self-closing/automatic-closing devices are crucial for fire doors.

Memory trick: Corridor 1-hour, door 20-minute, self-closing is the feature.

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