Which construction type is Type 5 in the common classification?

• A. Type 1: Fire resistive
• B. Type 5: Wood frame
• C. Type 3: Ordinary/Masonry
• D. Type 2: Noncombustible

Answer: (B)

Type 5 construction is wood-frame construction. In this classification system, the five types are defined by the materials and fire-resistance of the structural system: Type I is fire-resistive, Type II is noncombustible, Type III uses noncombustible exterior walls with some wood interior, Type IV is heavy timber, and Type V is built with wood for the structural frame. The key feature of Type 5 is that the structural members themselves are wood—light-frame or platform framing with studs, joists, and rafters. Because it uses highly combustible materials, Type 5 has the lowest inherent fire resistance among the common types, which is why wood-frame construction is the defining characteristic of Type 5.