Which construction type is typically fire-resistive and has the highest fire resistance ratings?

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

Answer: (A)

Fire-resistive construction means the structural members are protected so heat transfer is slowed and the building can maintain its integrity for a longer period during a fire. Type I is designed to be the most protective, using fireproofed or noncombustible materials for the frame, floors, and roof so the structure can withstand fire for multiple hours. That combination of materials and protection yields the highest fire-resistance ratings of the common construction types. In contrast, Type II uses noncombustible materials but typically without the same level of protective detailing, so its ratings are generally lower. Type III relies on noncombustible exterior walls with interior elements that can burn, and Type V uses wood framing, which offers the least inherent fire resistance. Therefore, Type I experiences the highest fire-resistance ratings.