Which construction type requires all structural members to be non-combustible materials?

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

Answer: (A)

Fire-resistive design focuses on keeping the structural system intact during a fire by using noncombustible materials for every main structural member and applying clear fire-resistance ratings to those members. Type I construction embodies this approach: columns, beams, floors, and roofs are all noncombustible and are designed to resist fire for specified durations, which is why it’s the construction type that requires all structural members to be noncombustible.

While Type II construction also uses noncombustible materials, its emphasis is on noncombustible components rather than the same explicit high fire-resistance ratings for every structural member. The other types incorporate combustible framing (such as wood interior framing in Type III or Type V, or heavy timber in Type IV), so they do not meet the criterion of all structural members being noncombustible.