Illinois Roofing Practice Exam

Which of these materials are most likely to cause more rapid deterioration in roofing systems with vaulted or cathedral ceilings?

1. Metal components.

2. Plastic materials.

3. Organic fibers.

4. Asphalt-based components installed over insulated non-vented decks.

The correct answer is: Asphalt-based components installed over insulated non-vented decks.

The choice that relates to more rapid deterioration in roofing systems with vaulted or cathedral ceilings is correct, as asphalt-based components installed over insulated non-vented decks can exacerbate moisture problems. In such systems, if inadequate ventilation exists and moisture accumulates, the trapped heat can lead to condensation. This creates an environment conducive to mold growth and deterioration of the roofing materials, significantly shortening their lifespan. Asphalt-based materials require proper ventilation to manage moisture effectively. Without it, especially in the sealed environment of a cathedral ceiling, these materials can break down more quickly due to the exacerbated effects of heat and moisture. In contrast, metal components and plastic materials can have different behaviors under such conditions. Metal may have longevity due to its durability, while plastic materials might not necessarily deteriorate at the same rate. Organic fibers, although susceptible to moisture, typically do not pose the same level of risk as asphalt-based components in the context of insulation and ventilation.