ICC Commercial Mechanical Practice Exam

In a private garage, ducts penetrating walls separating living spaces must be:

1. Continuous and made of sheet steel

2. Provided with openings into the garage

3. Made of any material as per preference

4. None of these

The correct answer is: Continuous and made of sheet steel

In a private garage, ducts that penetrate walls separating living spaces are required to be continuous and made of sheet steel to ensure safety and integrity of the building's mechanical system. This requirement is primarily linked to fire safety. Continuous ductwork reduces the potential for the spread of smoke and fire from the garage into living areas. Using sheet steel as the material for these ducts is crucial because it provides a robust barrier that can withstand higher temperatures and is less likely to melt or distort in a fire situation compared to other materials. This ensures that if there is a fire in the garage, the ducts do not contribute to the propagation of flames or smoke into the habitable spaces of the building. Other materials or configurations, such as those that are not continuous or do not provide suitable fire resistance, fail to meet the necessary safety standards for protecting occupied areas from the hazards that may arise in a garage environment. Therefore, the requirement for ducts to be made of sheet steel and continuous is a critical safety measure that is in line with building codes aimed at protecting occupants.