Which construction type is required to always have a collapse zone?

Type V construction is characterized by wooden frame construction that includes both walls and roofs made of combustible materials. Due to this construction method, Type V structures are particularly vulnerable to rapid collapse under fire conditions. Because of the potential for significant fire spread and weakened structural integrity, establishing a collapse zone is essential to ensure the safety of firefighters and other emergency personnel during firefighting operations.

A collapse zone is typically defined as the area surrounding a structure where there is a high risk of falling debris in the event of a failure. In the case of Type V buildings, the lightweight materials often used in their construction can weaken quickly when exposed to heat, making them more likely to fail, even in the early stages of a fire.

In contrast, Type I, Type II, and Type IV constructions are made with non-combustible or heavily fire-resistant materials, which generally afford them greater structural stability during a fire. As a result, while caution is always necessary while working in proximity to any structure during firefighting activities, the requirement for a collapse zone is most critical in Type V construction due to the inherent risks associated with its materials and design.