CLASS C ROOF ASSEMBLIES
Class C roof assemblies are those that are effective against light fire-test exposure. Class C roof assemblies and roof coverings shall be listed and identified as Class C by an approved testing agency.
This code implies that all roof materials that pass the testing provided in the ASTM E 108 fire testing under the light category are identified as Class C roof assemblies. The fire test standard – ASTM E 108 – tests roof assemblies for three fire categories; Severe, Moderate, and Light. The designation primarily differentiates between burn rates.
Roof assemblies with designation Class A or Class B can also be applied on Class C structures.
There are no specific materials or products that are automatically qualified as Class C roof coverings. Testing is required. Class C roof coverings that are listed and labeled by an approved testing agency may only be used on Types IIB, IIIB and VB construction.