What fire rating is required for vertical chases or openings in new construction of 4 or more stories?

In new construction that consists of four or more stories, a two-hour fire rating is typically required for vertical chases or openings. This requirement is crucial because vertical chases can allow fire and smoke to spread between floors if they are not adequately protected.

The two-hour rating serves as a barrier to limit the vertical movement of fire and smoke, providing essential time for evacuation and reducing the risk of fire spread through the structure. Additionally, building codes established by national standards, such as the International Building Code (IBC), reflect these requirements to ensure safety in multi-story buildings.

By ensuring that vertical openings meet this two-hour fire rating, building designs can provide a better level of safety for occupants and facilitate more effective fire-fighting efforts. This standard is widely recognized and helps maintain consistency across various jurisdictions in ensuring fire safety standards in taller structures.