Residential Building Inspector B1Building Planning and Life SafetyMedium
A builder is constructing a new detached garage on a property. The garage will be located 3 feet from the residential dwelling on the same lot. What is the minimum fire-resistance rating required for the exterior wall of the garage that faces the dwelling?
- A0-hour fire-resistance rating
- B1/2-hour fire-resistance rating
- C1-hour fire-resistance rating
- D2-hour fire-resistance rating
Show answer & explanationAnswer & explanation
Correct answer: C. 1-hour fire-resistance rating
According to the 2021 IRC, Table R302.1(1) Exterior Walls, detached garages located less than 5 feet from a dwelling on the same lot are required to have a minimum 1-hour fire-resistance rating for the exterior walls facing the dwelling.
Why the other options are wrong
- A. 0-hour rating is for walls more than 5 feet from a dwelling or property line.
- B. 1/2-hour rating is not a standard requirement for this scenario.
- D. 2-hour rating is typically for more severe exposure conditions or property line proximity.
Fire-Resistance Rating (Garage)
The duration for which a building component, such as a wall, can withstand exposure to fire without failing structurally or allowing fire passage.
- Depends on the distance to property lines or other structures.
- Protects adjacent structures from fire spread.
- Specified in IRC Table R302.1(1).
Memory trick: Distance dictates the fire wall's strength, keeping neighbors safe.