The toilet is vented through the sink drain. The toilet drain should be 3″, the sink drain is 1.5″, the shared sink drain/toilet vent area should be 2″, and the vent going up should be 1.5″. Also note that where the 2″ drain connects to the 3″ at the bottom the fitting should be a y instead of a tee as shown.
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]
Ready to remodel your kitchen or bathroom, but feel a little confused about the plumbing behind your sink? There's a lot to know about your sewage system before making any major changes, but it's easy to learn. With this article, you'll be a pipe ventilating DIY master in no time.
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
To keep the loop vent dry, that is so that the vent can work without flooding, the loop vent has to connect at the top of the fixture's vertical drain line, and the horizontal portion of the revent pipe must be at least 6-inches above the flood rim of the sink or other plumbing fixture being vented.
Usually, the vent pipe must extend six inches above the roof or 12 inches (30.5 cm) away from vertical walls, but double check your building codes and requirements to make sure. 4 Repeat the ventilation process with any other fixtures you're installing.