Residential Building Inspector B1Building Planning and Life SafetyEasy

A residential building inspector is reviewing plans for a new dwelling with an attached garage. The wall separating the garage from the dwelling is specified as a 1/2-inch gypsum board on the garage side. What is the minimum fire-resistance rating required for this wall?

  1. A0-hour fire-resistance rating
  2. B1/2-hour fire-resistance rating
  3. C1-hour fire-resistance rating
  4. D2-hour fire-resistance rating
Show answer & explanation

Correct answer: B. 1/2-hour fire-resistance rating

Walls separating a garage from a dwelling are critical for fire safety, preventing the spread of fire from the garage into the habitable space. The IRC specifies a minimum fire-resistance rating for such assemblies.

Why the other options are wrong

  • A. A 0-hour rating provides no fire separation and is not permitted.
  • C. While providing more protection, 1-hour is not the minimum required for this specific assembly.
  • D. This rating is excessive for the minimum requirement of this assembly.

Garage-Dwelling Separation Fire Rating

Walls, ceilings, and other elements separating a garage from a dwelling must meet specific fire-resistance ratings to limit fire spread.

  • Protects occupants from garage fires.
  • Specific ratings for walls, ceilings, and doors.
  • Typically achieved with gypsum board.

Memory trick: Garage to dwelling, half-hour telling, fire's hold, quickly quelling.

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