A building with a metal deck roof is classified as which NFPA 220 construction type?

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

Answer: (D)

NFPA 220 classifies buildings by whether the structural frame and exterior walls are noncombustible. A metal deck roof is noncombustible, and when the main structural frame is also noncombustible, the overall construction falls into the noncombustible category. That is Type II. This type contrasts with fire-resistive Type I (which uses heavily protected, fire-resistive assemblies), Type III (ordinary construction with noncombustible exterior walls but potentially combustible interior framing), Type IV (heavy timber), and Type V (wood frame). So a building with a metal roof deck lines up with noncombustible construction, i.e., Type II.