Which of the following is NOT one of the six main roof architectural types?

The distinction of the six main roof architectural types typically includes flat, hip, gable, mansard, shed, and saltbox roofs. The choice labeled arched gimbal does not align with these recognized categories.

Arched gimbal roofs are not considered a standard type in architectural terminology. The main roof types are generally categorized based on their geometric shape and structural design. A flat roof is characterized by a horizontal surface, while a hip roof slopes upward on all sides, and a gable roof features two sloped sides that meet at a peak. Each of these types serves specific architectural and functional purposes.

Understanding the main roof types is essential for assessments related to lightning protection, as different roof shapes may have varying implications for the installation of lightning protection systems.