Type IV construction utilizes which of the following structural members?

• A. 8-inch square posts supporting 14-inch deep wood beams
• B. 6-inch square posts supporting 12-inch deep wood beams
• C. 10-inch round posts supporting 16-inch deep wood beams
• D. 4-inch square posts supporting 8-inch deep wood beams

Answer: (A)

Type IV construction relies on large, solid timber members for the structural frame. The hallmark is heavy timber: posts and beams with substantial cross-sections that provide strength and fire resistance. An arrangement with 8-inch square posts and very deep beams (14 inches) fits this approach, since the posts meet the minimum robust size and the beams are deep enough to be considered heavy timber. The other options use smaller or less substantial members (smaller post sizes or non-typical round posts, and thinner beam sections), which do not align with the heavy timber requirements of Type IV.