Final answer:
The pipe in question is called the vent stack. It is visible in the attic and emerges from the roof surface, allowing for proper gas escape and air entrance into the plumbing system.
Step-by-step explanation:
The extension of a soil or waste stack above the highest horizontal drain that is connected to the stack is known as the vent stack. This component of the plumbing system is crucial as it allows gases to escape and permits air to enter the system, making sure that the wastewater flows properly. You can often see the vent stack protruding through the attic and extending out of the roof surface of a building.
The vent stack is an essential component of a plumbing system, helping to maintain proper pressure and preventing the formation of a vacuum in the drain pipes. The visible portion of the vent stack is often seen on the roof and may be equipped with a vent cap to protect it from debris and the elements.
The vent stack is crucial for the proper functioning of a plumbing system, and its design and installation are subject to local plumbing codes and regulations. Always consult local codes and guidelines to ensure compliance with plumbing standards in your area.