Exterior walls on Type III buildings are typically made of which materials?

• A. Brick, block, steel studs with brick veneer
• B. Wood framing
• C. Glass curtain walls with aluminum
• D. Solid stone

Answer: (A)

In Type III construction, exterior walls must be noncombustible, typically masonry such as brick or concrete block. The interior structure behind those walls can be wood or steel framing. A very common modern arrangement is a masonry exterior (brick or block) with a steel-stud interior frame and brick veneer on the outside. This combination gives the fire-resistant, noncombustible exterior while keeping the interior framework lighter and more economical. The other options don’t fit as neatly: wood framing would involve combustible material in the exterior wall assembly, glass curtain walls with aluminum are not the typical full exterior wall material for Type III, and while solid stone is noncombustible, brick or block with brick veneer on steel studs is far more common in practice.