North Carolina Building Contractor License Practice Exam

What does flame spread refer to?

1. The rate at which flame travels across a surface

2. The resistance of a material to fire

3. The intensity of heat produced by a flame

4. The ignition point of flammable materials

The correct answer is: The rate at which flame travels across a surface

Flame spread describes the rate at which a flame propagates across a material's surface. This characteristic is critical in assessing fire safety, particularly in building materials used in construction. Understanding flame spread helps determine how quickly a fire can spread within a space, which is vital for ensuring occupant safety and effective evacuation during a fire incident. Building codes often refer to flame spread ratings to mandate the use of materials that minimize the risk of rapid fire spread, thus contributing to the overall fire-resistance strategy of structures. The other concepts presented in the other choices refer to different aspects of fire behavior and material properties. The resistance of a material to fire, for example, pertains to its ability to withstand heat without degrading, which is not the same as how quickly a flame may move across it. Similarly, the intensity of heat produced by a flame concerns the energy output of a fire rather than its spread, and the ignition point of flammable materials focuses on the conditions necessary for fire to start, rather than its propagation once it has begun. Understanding flame spread specifically emphasizes the speed of fire transmission across surfaces, making it a crucial component in fire safety assessments.