Which factor most affects the risk of collapse for Type II (noncombustible) construction during a fire?

• A. Exposure to high heat over time weakening connections.
• B. It cannot collapse.
• C. It is steel-framed.
• D. It has no fuel.

Answer: (A)

The key idea is that for Type II construction, which uses noncombustible materials, the biggest danger to collapse during a fire comes from how heat weakens the steel connections and members over time. Even though the structure itself isn’t burning, high temperatures can reduce the strength of steel and, crucially, the joints that transfer loads between beams and columns. If those connections lose their ability to carry shear, tension, or compression, the frame can no longer support itself, leading to progressive failure and potential collapse.

So, exposure to high heat over time weakening connections is the driving factor because it directly undermines the load paths that keep the building standing. The other statements don’t describe this mechanism: simply being steel-framed doesn’t by itself determine collapse risk, and noncombustible construction doesn’t guarantee no collapse. Also, having no fuel doesn’t mean the structure can’t heat up and fail—the fire’s heat, not just the presence of fuel, drives the weakening of structural connections.