Which plumbing fixtures usually require a separate vent?

Separate venting for plumbing fixtures is crucial for maintaining proper drainage and preventing sewer gases from entering the living space. Floor drains and sinks often require individual venting due to their specific wastewater management needs.

Floor drains are typically installed in basements or areas prone to water accumulation, and they need a vent to function effectively. This is because the drain must be able to maintain a proper air pressure in the drainage system, allowing wastewater to flow freely without creating a vacuum that could hinder drainage.

Sinks, on the other hand, have a more complex drainage system that can trap air and create siphoning effects. A separate vent helps ensure that air can enter the drainage system, preventing slow drainage and potential backups. This venting requirement helps to accommodate for the varying flow rates and potential blockages in the system, ensuring that both floor drains and sinks operate efficiently.

Together, the unique features and functions of floor drains and sinks justify the need for separate venting systems in order to ensure optimal performance and compliance with plumbing codes.