North Carolina Building Contractor License Practice Exam

In what manner must roof covering be applied to combustible roof insulation for it to be permissible?

1. Directly over the insulation

2. With a vapor barrier

3. Indirectly via a base layer

4. Not applicable, must use non-combustible

The correct answer is: Directly over the insulation

Roof coverings applied to combustible roof insulation must be installed directly over the insulation to be permissible. This approach is often required because it allows for the roof covering to act as a protective barrier, minimizing the risk of fire spreading through the insulation material. Direct application can also ensure that the roof covering adheres properly, providing effective waterproofing and structural integrity. In the context of building codes and fire safety regulations, this method helps to mitigate the potential hazards associated with combustible materials, ensuring that the roof system as a whole can withstand certain fire conditions without compromising the underlying insulation. The choice of direct application signifies adherence to safety standards that aim to reduce the risk of fire incidents in structures with combustible insulation. Alternative methods, such as using a vapor barrier or a base layer, may not provide the same level of direct protection or compliance with fire safety guidelines. Additionally, the option of using non-combustible materials is more restrictive, as it implies that combustible insulation cannot be utilized at all, which is not the case if the roof covering is applied correctly.