You should plan for a collapse zone at any fire incident with what type of building construction?

• A. Type V
• B. Type II
• C. Type I
• D. Type III

Answer: (A)

Wood-frame construction (Type V) is the most prone to rapid collapse when exposed to fire, so you plan for a collapse zone at incidents involving it. The framing is highly combustibile, often with lightweight or engineered members that can fail quickly as heat builds, and interiors can burn unseen behind walls or floors. When these members give way, debris can fall straight down or outward, creating a dangerous area surrounding the building. Establishing a collapse zone helps keep crews out of that danger and gives time to reassess as conditions change.

Other construction types tend to have more inherent fire resistance or different failure patterns. Noncombustible (Type II) and fire-resistive (Type I) buildings are less likely to experience a sudden, complete collapse from fire, while Type III has a masonry exterior with a wood interior, which can fail but isn’t as uniformly prone to rapid collapse as Type V. Still, always evaluate the specific building and fire conditions, but the priority for planning a collapse zone is strongest with Type V structures.