What does the term 'ridge drop' indicate in roofing?

The term 'ridge drop' refers specifically to the vertical distance that the ridge of the roof drops to meet the edge of the rafter. This measurement is essential for ensuring that the roof structure maintains proper drainage and alignment. It impacts the overall performance and aesthetics of the roof, including how water flows off the roof and how the roof integrates with the walls and other structural elements. When designing or assessing a roofing system, understanding ridge drop helps in maintaining the correct slope and ensuring that the roof is well-constructed to prevent leaks and other issues.

The other options do not accurately describe the meaning of ridge drop, focusing on different aspects of the roofing system, such as distances or measurements related to the rafters or angles, which are separate considerations in roofing design.