What is the maximum flame spread rating class for wall and ceiling finishes in a structure?

In building code regulations, the flame spread rating of wall and ceiling finishes is categorized according to standards set forth by the National Fire Protection Association (NFPA) and other regulatory bodies. The maximum flame spread rating that is generally permissible for wall and ceiling finishes in most residential construction is designed to limit the potential for fire to spread rapidly, thereby enhancing safety.

A flame spread rating of 200 is often considered the upper limit for certain occupancies, allowing finishes that are more fire-resistant but still functional in terms of aesthetics and usability. This rating indicates that the material can be used in most residential applications without significant risk of contributing to the rapid spread of fire.

In contrast, a rating of 100 signifies a more stringent requirement, typically reserved for specific high-risk areas or specialized applications, while ratings of 250 and higher are generally not acceptable for residential structures as they indicate materials that can contribute to a more dangerous fire scenario. Therefore, the correct answer reflects the balance between safety and practicality in everyday residential building practices.