42. A 25,000 square foot commercial building is to have a class B modified bitumen roof covering. MINIMUM R-19 insulation is REQUIRED. Combustible insulation is permitted when the
Answer: D
Combustible insulation is permitted when the roof covering has a flash point above 400 degrees F.
Combustible insulation can be utilized as long as the roof covering has a flash point above 400 degrees Fahrenheit, ensuring that the materials used maintain safety standards in terms of fire resistance.
A) building is not located in a fire district.
This option is incorrect because the location of the building, whether in a fire district or not, does not determine the permissibility of using combustible insulation. The critical factor is the fire performance characteristics of the roof covering itself, not the geographical designation.
B) roof covering is applied directly to the insulation.
This statement is incorrect as well. The application of the roof covering directly to the insulation does not inherently make combustible insulation permissible. The safety considerations are based on the fire performance characteristics of the roof covering, specifically its flash point.
C) building is not classified as assembly occupancy.
This choice is also incorrect. The classification of the building as assembly occupancy does not influence the allowance of combustible insulation. The essential criterion is based on the fire safety characteristics of the roof covering rather than the specific use or occupancy of the building.
D) roof covering has a flash point above 400 degrees F.
This option is correct. When the roof covering has a flash point above 400 degrees Fahrenheit, it indicates a higher level of fire resistance, allowing for the use of combustible insulation in accordance with safety regulations.
Conclusion
The correct answer is option D, as it directly addresses the conditions under which combustible insulation is permitted based on the fire performance characteristics of the roof covering. Options A, B, and C fail to consider the critical factor of the roof covering's flash point, which is essential for determining the safety and compliance of the insulation used. Therefore, only option D aligns with the necessary safety standards for the specified roofing system.