Type IV construction's performance is driven by which component?

• A. Roofing material
• B. Insulation type
• C. Drywall finish
• D. Connection Hardware

Answer: (D)

In Type IV construction, the way the heavy timber frame stays together under load and through fire is dominated by the connection hardware. The large wood members provide the main strength, but it’s the bolts, plates, brackets, and other fasteners that transfer forces between members and keep the frame from pulling apart or sliding at the joints. If these hardware components lose strength, deform, or fail under heat, the whole structure can collapse even if the timber itself remains comparatively intact. So, the performance of a Type IV frame hinges on how well the connection hardware performs, including its fire resistance and ability to maintain alignment. Roofing, insulation, or drywall affect fire reaction in other ways but do not control the structural behavior of the timber frame the way joints and connectors do.