What is the primary function of a vent stack?

The primary function of a vent stack is to allow sewer gases to escape and to equalize pressure in the drainage system. Vent stacks are essential components of plumbing systems that serve as a pathway for air to enter the drainage system, which helps to prevent a vacuum from forming when wastewater is drained. This balance of pressure is crucial as it ensures that wastewater flows smoothly through the pipes without creating backflow or siphoning out water from traps, which could expose the home to sewer gases.

Additionally, allowing sewer gases to escape prevents hazardous fumes from accumulating within a building, thereby improving indoor air quality and maintaining a safe environment. The design and placement of vent stacks are guided by plumbing codes to ensure that they effectively perform this vital role in the overall plumbing system.