In NFPA 101, which occupancy is often associated with heavy timber and is categorized as Type II?

• A. Heavy timber
• B. Less fire resistant than Type I
• C. Masonry walls and wood roof
• D. Ordinary construction

Answer: (A)

In NFPA 101, construction types define how a building is built and how it will perform in a fire. There are five types, based on materials and fire resistance: Type I (fire-resistive), Type II (noncombustible), Type III (ordinary with noncombustible exterior walls), Type IV (heavy timber), and Type V (wood frame). Heavy timber is specifically associated with Type IV construction, which uses large solid wood members that charring protects and retards fire spread due to their mass. Type II, by contrast, is noncombustible framing (steel or concrete) and does not rely on heavy timber. So, the concept to remember is that heavy timber corresponds to Type IV, not Type II; if a source states heavy timber is Type II, that is a misstatement of the construction type classifications.