Residential Building Inspector B1Building Planning and Life SafetyMedium
A residential building inspector is reviewing plans for a new single-family dwelling. The plans indicate the installation of a new gas-fired water heater in the garage. What is the minimum height above the garage floor that the ignition source of this water heater must be located?
- A24 inches
- B18 inches
- C6 inches
- D12 inches
Show answer & explanationAnswer & explanation
Correct answer: B. 18 inches
According to IRC G2408.2 (305.5), appliances in a private garage shall be installed with an ignition source and burners located not less than 18 inches (457 mm) above the floor. This requirement is to prevent ignition of flammable vapors that might accumulate near the floor.
Why the other options are wrong
- A. This height exceeds the minimum requirement but is not the minimum.
- C. This height is insufficient to prevent ignition of common flammable vapors.
- D. This height is insufficient to prevent ignition of common flammable vapors.
Garage Appliance Ignition Height
Minimum height for ignition sources of fuel-fired appliances installed in a garage to prevent ignition of flammable vapors.
- Protects against fire/explosion.
- Applies to gas, oil, and other fuel-fired appliances.
- Vapors are heavier than air and settle low.
Memory trick: In the garage, where fumes might roam, 18 inches high, ignition finds its home.