Which material is not typically metal building material?

• A. Wood
• B. Cast iron
• C. Steel
• D. Aluminum

Answer: (A)

In building materials, metals are chosen for structural strength and stiffness, while non-metals are selected for other properties like insulative value, weight, or ease of work. Metals such as cast iron, steel, and aluminum are used for structural members, fasteners, and components that need high strength and durability. Wood, however, is not a metal; it’s an organic material commonly used for framing and finishes but it doesn’t have the same metallic properties, such as high stiffness per weight and corrosion resistance, that metals provide. So the material that is not typically metal for building use is wood.