Nonclassified roofing material is not listed under which classification?

Nonclassified roofing materials are those that do not meet the established performance criteria set forth by the National Fire Protection Association (NFPA) or similar regulations. The classifications—Class A, B, and C—are based on the material's ability to withstand fire exposure and the extent to which it can prevent fire from spreading.

Class A roofing materials are considered to have the highest fire resistance, providing a significant barrier to external fire elements. Class B materials have moderate fire resistance, and while they offer some level of protection, they are not as robust as Class A. Class C materials are generally regarded as having a lower fire resistance compared to Class A and B materials.

The classification system is designed to help building inspectors, designers, and builders select appropriate materials that align with the safety standards necessary for various building types and local codes. Since nonclassified roofing materials lack any formal classification under these categories and do not meet the fire performance criteria, they truly are not included in any of the classifications identified for roofing materials. This leads to the understanding that nonclassified roofing materials are effectively excluded from all Class A, Class B, and Class C categories, which justifies the choice indicating that they are not listed under any of these classifications.