When my house was built they included the "rough ins" for a basement bathroom. Due to what we wanted to finish in the basement we had them move the rough ins 6ft 6ins. Now that I'm in the process of finishing the basement, I'm dealing with a vent stack on the opposite side of the bathroom from where the sink and toilet will be. I will be boxing down over the shower 8" to put a recessed light centered (wife's request). My plan is to bring the vent stack over in the front of that boxout, take it up the opposite wall and then to 90 degree angles close together to match up with the vent stack. The vent stack sticks down about 4" from the wall, between the same floor joists as the wall.

Now, I had assumed that there wouldn't be any problems with this since its just air passing through the vent. However, I had a drywaller stop by (the only thing I'm contracting out) and he said that he ran into problems doing something similar. He said that if there is too much horizontal run you will run into trouble. Can't I just run one pipe up and over? Should my drywaller just stick to his trade?

Thank you,

- TL

Tell your drywaller not to quit his day job because he's dead wrong. Slope the horizontal line back to your bathroom group and you'll be just fine. Good luck, Tom

Tom said it. It is absolutely OK to reroute it to the opposite wall through the dropped ceiling. Maintain 1/4" back slope and use at least medium turn 90s.. and you will be fine.