What component is typically indicated by an arrow pointing in roof framing photos?

In roofing terminology, an arrow pointing in roof framing photos usually indicates a purlin. Purlins are horizontal beams that are positioned perpendicularly to the rafters and are used to support the roof deck or sheathing in some roofing systems. They play a critical role in distributing the load of the roofing materials and help provide additional structural support.

While other components of roof framing, such as rafters, ridge boards, and strongbacks, each have distinct functions, they are typically identified differently in framing photos. Rafters are the inclined beams that run from the ridge down to the eaves, contributing to the overall slope of the roof. The ridge board is a horizontal member at the peak of the roof, serving as a support for the upper ends of the rafters. Strongbacks are temporary or permanent braces between rafters or joists that provide additional stability but are not usually marked in the same way as purlins in photographs.