Which option correctly matches a building construction type with its key fire-behavior implication?

• A. Type I (fire-resistive) – slower fire spread.
• B. Type II (noncombustible) – interior concealed spaces.
• C. Type III (ordinary) – large dimension lumber, slower collapse.
• D. Type IV (heavy timber) – interior concealed spaces.

Answer: (A)

The key idea here is how fire-resistive construction behaves in a fire. Type I, fire-resistive buildings are built with rated, noncombustible materials and protected structural elements that resist heat and maintain integrity longer. That means the fire is less able to spread quickly through floors, walls, and connections, so the overall spread is slowed. This is the strongest, most consistent fire-behavior implication for Type I.

Interior concealed spaces, while a concern in many building types, aren’t the defining fire-behavior trait of noncombustible construction. Similarly, large-dimension lumber is associated with heavy timber (Type IV) rather than ordinary Type III framing, and interior concealed spaces aren’t the hallmark feature of Type IV either. So the statement about slower fire spread best matches Type I.