ICC Commercial Building Inspector Practice Test

For wall and ceiling finishes, what is the index classification range for Class C as per ASTM E 84?

1. 0-25

2. 26-75

3. 76-200

4. 201-500

The correct answer is: 76-200

The index classification for Class C finishes according to ASTM E 84 is in the range of 76-200. This standard, commonly known as the "Steiner Tunnel Test," measures the surface burning characteristics of building materials. Understanding the classification ranges is essential for evaluating the fire safety of materials used in construction. Class C materials have a higher potential for flame spread as compared to Classes A and B. Class A has an index classification of 0-25, indicating a very low flame spread, while Class B is in the range of 26-75, indicating a moderate flame spread. Class C materials can be found in various applications where lower fire ratings are acceptable, but they are not suitable for scenarios that require higher fire resistance. Recognizing these classifications is vital for compliance with building codes and ensuring safety in commercial buildings.