What material must interior walls and partitions be made from in buildings of Type I or II construction?

In buildings of Type I or II construction, interior walls and partitions are required to be made from noncombustible or limited-combustible materials. This requirement is rooted in fire safety regulations aimed at minimizing the risk of fire spread within the building. Noncombustible materials, such as concrete, brick, or steel, do not ignite or contribute to the fire load, while limited-combustible materials, such as some specific treated materials, have a reduced potential to burn.

The emphasis on using these types of materials aligns with the intent of Type I and II construction, which is designed to provide a higher level of fire resistance compared to other construction types. Ensuring that interior walls and partitions are constructed from these materials plays a significant role in protecting occupant safety and enhancing the overall fire-resistance rating of the structure.

Other materials, such as wood, could contribute significantly to fire hazards due to their combustibility, thereby making them unsuitable for such construction types. Thus, choosing noncombustible or limited-combustible materials is critical for compliance with building codes and for ensuring a safe environment in these types of buildings.