The enclosures for interior exit stairways and ramps must be constructed as:

The enclosures for interior exit stairways and ramps must be constructed as either fire barriers or horizontal assemblies to ensure optimal safety and protection during an emergency, such as a fire. Fire barriers are specially designed walls or partitions that can prevent the spread of fire and smoke for a specific duration, providing safe passage for occupants who are evacuating. Horizontal assemblies, which can include ceilings or floors that form a barrier against fire, also serve a critical role in maintaining a safe environment within the structure.

Using either of these construction methods enhances the overall fire-resistance rating of the exit enclosures, ensuring that they provide a protected route for evacuating occupants. This flexibility allows for different construction methods depending on the design and materials of the building, while still adhering to safety regulations and standards for exit enclosures.