Materials used as interior trim must have a minimum Class _____ flame spread.

Interior trim materials are crucial in determining the fire safety of a building. The flame spread classification system offers an important measure for assessing the fire performance of building materials, particularly in occupied spaces. A Class C flame spread rating indicates that the material can withstand a moderate level of flame spread in the event of a fire, providing an acceptable level of safety for interior environments.

This classification is particularly relevant because it aligns with building codes that dictate safety standards for materials used in various parts of a building. Class C materials are commonly accepted for interior trim in many applications, striking a balance between aesthetic appeal and fire safety. This makes them suitable for a variety of settings while ensuring that they meet building regulations designed to protect occupants during emergencies.

In contrast, materials classified as A or B would provide lower flame spread ratings, which may be required for other applications but are not typically necessary for standard interior trim where Class C suffices. Thus, the regulation that stipulates a minimum of Class C ensures that trim materials contribute to the overall safety and compliance of the building’s interior design.