plumbing venting

Before.

(sink, trap, vent)

Generally the main vent stacks are installed behind the wall and all the waste water drains are installed off of them.

Plumbing vents are a vital part of indoor plumbing systems, but few people outside the plumbing industry know much about them. A basic understanding of the purpose and workings of plumbing vents can help any homeowner avoid dangers and take care of basic plumbing maintenance.

Thanks in advance,
Amalia

We always put the vent on the leaving side of the trap. Make sure the end of vent pipe is higher than the drain pan