What does the acronym "OC" stand for in roofing?

In the context of roofing, the acronym "OC" stands for "On Center." This term is commonly used in construction and roofing to indicate the spacing between materials, such as rafters, studs, or roof panels, measured from the center of one element to the center of the next. This precise measurement is crucial for ensuring structural integrity and proper alignment during installation. For example, if rafters are set 16 inches OC, it means each rafter is spaced 16 inches apart measured from the center of one rafter to the center of the next.

Understanding "On Center" is essential for roofers as it establishes a standardized approach for installations, allowing for consistent support for roofing materials and proper alignment of components throughout the roofing system.