In Type III construction, interior structural members are typically made of which material?

In Type III construction, interior structural members are typically made of which material?

• A. Concrete
• B. Wood
• C. Steel
• D. Brick

Answer: (B)

Type III construction uses exterior walls built of noncombustible materials, while the interior framing is allowed to be combustible. Wood is the typical material for those interior structural members because it’s economical, familiar to builders, and adequate for ordinary structures within the code’s allowances. Exterior noncombustible walls resist direct flame exposure from outside, but the interior wood framing means fires can spread more quickly inside once ignited. Concrete or brick interior members aren’t the standard for this type, and steel can be used but isn’t the usual choice for interior framing in ordinary Type III buildings.

Type III construction uses exterior walls built of noncombustible materials, while the interior framing is allowed to be combustible. Wood is the typical material for those interior structural members because it’s economical, familiar to builders, and adequate for ordinary structures within the code’s allowances. Exterior noncombustible walls resist direct flame exposure from outside, but the interior wood framing means fires can spread more quickly inside once ignited. Concrete or brick interior members aren’t the standard for this type, and steel can be used but isn’t the usual choice for interior framing in ordinary Type III buildings.