Bathroom Sink Venting Requirements
Drain and vent lines are important aspects of your home's sewer system. We'll show you why they matter and how to install them yourself. Installing drain and vent lines in your bathroom is a home project that can be completed in a weekend. Before you begin, have your plans approved by an inspector
Vents exist primarily to allow air exchange in the pipes while water is flowing. Without them, the rushing water creates a vacuum that can slow the water or even stop it and can exert enough internal pressure on the pipes to crack joints. The plumbing code has specific requirements regarding pipe size and placement of sink vents.
No bathroom plumbing system is complete without ventilation. When you flush the commode or drain the tub, wastewater pushes the existing air in the pipes and can form a water lock if additional
vent is based on the pipe size . (See Table on page 64) 2 903 .1 3107 .1 A vent system serving each building drain must have at least one pipe that extends to the outdoors . (See additional requirements on page 26) 3 908 .1 3107 .1 An individual vent is allowed to vent two traps or trapped fixtures . (See additional requirements in the IPC
An island vent rises as high as possible under an island before running to a regular vertical vent. It keeps air in the drain system and prevents siphoning of the P-trap. Tip: If you plan to attach a garbage disposer to an island sink, replace the sanitary tee and cleanout adapter with a flat-patterned cleanout tee.
Every bathroom requires an openable window that provides at least 1.5 square ft of air flow area when open - 2006 IRC [303.3] OR mechanical type ventilation: 50 CFM intermittent or 20 CFM continuous operation - 2006 IRC [303.3X]