Which roof rating is described as the highest in fire resistance?

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

Answer: (B)

Roof fire-resistance ratings use a Class system to show how well a covering resists flames and heat. The higher the class, the more resistant the roof is to ignition and to the spread of fire. Class A is the top tier, providing the greatest resistance to flame spread and ember intrusion under standard fire exposure tests. This level of performance is especially important in wildfire-prone areas, where a Class A roof helps slow fire progression and reduces the likelihood of external flames igniting the roof. The lower classes indicate progressively less resistance, and there isn’t a recognized Class D rating in this system.