Which construction feature is associated with higher collapse risk?

Which construction feature is associated with higher collapse risk?

• A. Lightweight or engineered wood framing.
• B. Solid reinforced concrete columns.
• C. Non-load-bearing plaster walls.
• D. Masonry block walls with no fire exposure.

Answer: (A)

Lightweight or engineered wood framing is the construction feature most tied to higher collapse risk in a fire. These systems use slender, fuel-rich members that burn quickly, lose strength rapidly when heated, and have less inherent redundancy. As heat penetrates, connections and fasteners soften and fail, allowing floors and roofs to give way sooner and with less warning. In contrast, solid reinforced concrete columns resist heat better and maintain load-bearing capacity longer, non-load-bearing plaster walls don’t carry structural loads, and masonry block walls—while heavy—are less prone to rapid collapse if they have not been damaged by fire exposure. So the rapid degradation of lightweight wood framing under fire is the key reason it is associated with greater collapse risk.

Lightweight or engineered wood framing is the construction feature most tied to higher collapse risk in a fire. These systems use slender, fuel-rich members that burn quickly, lose strength rapidly when heated, and have less inherent redundancy. As heat penetrates, connections and fasteners soften and fail, allowing floors and roofs to give way sooner and with less warning. In contrast, solid reinforced concrete columns resist heat better and maintain load-bearing capacity longer, non-load-bearing plaster walls don’t carry structural loads, and masonry block walls—while heavy—are less prone to rapid collapse if they have not been damaged by fire exposure. So the rapid degradation of lightweight wood framing under fire is the key reason it is associated with greater collapse risk.