California IDEX Practice Exam

Ducts penetrating a 1-hour rated partition require...

1. Smoke detectors

2. Fire dampers

3. Intumescent paint

4. High-temperature insulation

The correct answer is: Fire dampers

The correct answer is fire dampers. Ducts that penetrate a 1-hour rated partition need to maintain the fire-resistance rating of that partition. Fire dampers are specifically designed to prevent the passage of flames and smoke through ductwork when a fire occurs. By automatically closing when a certain temperature is reached, fire dampers help to contain fire and smoke within a compartment, ensuring that the integrity of the 1-hour rated wall is upheld. In the context of the other options: smoke detectors are important for early fire detection, but they do not serve to physically block fire spread through ducts. Intumescent paint is used to coat materials to enhance their fire-resistance but does not apply directly to duct systems. High-temperature insulation is relevant for ductwork but primarily for protecting against heat, not for preventing fire spread through rated assemblies.