North Carolina Building Contractor License Practice Exam

What maximum height must combustible insulating boards be when attached to a non-combustible floor?

1. 24 inches

2. 36 inches

3. 42 inches

4. 48 inches

The correct answer is: 42 inches

The maximum height for combustible insulating boards attached to a non-combustible floor must be 42 inches. This regulation is in place to mitigate fire risks by establishing a height limit for materials that can potentially ignite easily when installed in specific conditions. Combustible insulating boards have a higher flame spread rating and when installed at a significant height above non-combustible surfaces, they pose a greater risk of contributing to the spread of fire. The specified limit of 42 inches serves as a safety measure, ensuring that any potential ignition does not extend toward the main body of the building and provides a buffer zone for fire containment. The determination of this height is informed by fire safety codes and building regulations, which dictate how combustible materials can be used in construction to optimize safety and reduce fire hazards in buildings. Therefore, understanding these criteria is vital for compliance with building codes and ensuring the safety of a constructed environment.