How many fixtures can be served by a single vent?

A single vent typically serves no more than six fixtures in a plumbing system. This guideline is rooted in plumbing codes and standards to ensure proper venting of waste and sewage from the fixtures, allowing for the efficient operation of the drainage system. The purpose of a vent is to allow air to enter the plumbing system, ensuring that water flows smoothly and preventing the risk of siphoning water from traps, which could allow sewer gases to enter living spaces.

When a vent serves too many fixtures, it can lead to inadequate ventilation, resulting in slow drainage, unpleasant odors, and increased risk of blockages. Having a maximum of six fixtures per vent helps maintain an optimal airflow, facilitating proper drainage and ensuring that the system can handle fluctuations in pressure effectively. This regulation helps to maintain a safe and functioning plumbing environment.