Which part of the plumbing system extends and goes through the roof?

The stack vent is the segment of the plumbing system that extends through the roof. This component plays a crucial role in maintaining proper drainage and waste management within the plumbing system. It allows air to enter the waste drainage system, ensuring that waste can flow freely and preventing any vacuum that could cause issues such as slow drainage or gurgling sounds in the plumbing.

The stack vent typically connects to the vertical waste stack, which carries wastewater down from various fixtures in the building. By extending above the roofline, the stack vent is designed to expel sewer gases safely away from the building, helping to maintain a healthy indoor environment.

In essence, the stack vent is vital for the functioning and safety of the plumbing system, as it not only facilitates proper drainage but also ensures that harmful gases do not enter living spaces.