Which material classification is not permitted for use by a contractor?

Which material classification is not permitted for use by a contractor?

• A. Class A
• B. Class B
• C. Class C
• D. Class D

Answer: (D)

Fire performance ratings for roof coverings come in three recognized classes: Class A, Class B, and Class C. These ratings reflect how well a material resists fire, with Class A offering the highest fire resistance, Class B less, and Class C the lowest. Building codes and roofing product listings are built around these recognized classifications, so a material that carries a rating of Class D does not meet the established fire-safety standards and cannot be used by a contractor under typical code requirements. If you encounter a product claiming Class D, you should avoid it and choose a Class A, Class B, or Class C rated material that complies with the code and the product’s listing.

Fire performance ratings for roof coverings come in three recognized classes: Class A, Class B, and Class C. These ratings reflect how well a material resists fire, with Class A offering the highest fire resistance, Class B less, and Class C the lowest. Building codes and roofing product listings are built around these recognized classifications, so a material that carries a rating of Class D does not meet the established fire-safety standards and cannot be used by a contractor under typical code requirements. If you encounter a product claiming Class D, you should avoid it and choose a Class A, Class B, or Class C rated material that complies with the code and the product’s listing.