What is referred to as a vertical rainwater pipe in building plumbing?

A vertical rainwater pipe in building plumbing is referred to as a rainwater leader. This pipe is specifically designed to collect and direct rainwater from areas such as rooftops down to the ground level or to a drainage system. Rainwater leaders play a crucial role in preventing water damage to structures by ensuring that rainwater is effectively channeled away from the building.

In contrast, other options refer to different aspects of plumbing systems. For example, a soil pipe is primarily used for the discharge of wastewater and sewage, while a drainage stack serves as a vertical pipe that conveys both wastewater and venting material through the building. A roof scupper is a drainage installation that allows rainwater to flow off the roof; however, it does not serve the purpose of transporting rainwater vertically like a rainwater leader does. Therefore, the specific function and design of a rainwater leader make it the correct term for a vertical rainwater pipe in building plumbing.