Drainage, Waste & VentQuestion 129 of 360

In a bathroom-group wet vent, where is the dry vent connection typically made?

a.At the most upstream fixture drain, so the vent draws through the wet-vented section
b.At the water closet only
c.At the most downstream fixture
d.At the bathtub trap arm exclusively

Explanation

The dry vent for a wet-vented bathroom group is connected at the drain of the most upstream fixture (commonly a lavatory). Air is then drawn through the wet-vented drain to protect the downstream fixture traps. The water closet is usually the most downstream fixture on the wet-vented branch.

Law Reference: 2022 California Plumbing Code (CPC) §908.0

Practice all 360 questions free — no signup required.

Related questions on this topic

Last reviewed: · editorial process

PrepPass Editorial Team · Verified against California CSLB C-36 Plumbing Trade Examination · How we review
Report