In a Seabee BU A School context, what are the primary structural members of a PEB frame?

• A. Columns and beams form the primary frame, with rafters for roof support.
• B. Only columns form the primary frame.
• C. Only beams form the primary frame.
• D. Rafters form the entire primary frame.

Answer: (D)

In a PEB frame, the main load path and the defining skeleton of the roof are set by the members that carry the roof loads directly. Rafters span between columns and form the roof-supporting framework, establishing the building’s shape and rigidity. Columns provide vertical support and transfer loads to the foundation, but the primary frame—the part that defines the roof‑frame geometry and carries the roof loads—is formed by the rafters. That’s why this option best fits how the PEB frame’s main structural system is described in this context.