I need to move a 3" main vent 12 inches from original place in a wall from crawl space to attic but do not want to move exit point in roof can I do so and angle in attic to tie back in exit point

Hi Chillbille

Yes, you can offset the stack. Use as few 90s as possible... 45 degree fittings/offsets are best, OK?

Mark

I am adding a whole separate bath at the other end of my house,about 25 feet from the other bath.Can I vent the toleit, sink and tub on a single 2 inch line. I will be running a 3 inch drain to the main line which by the way is septic

Yes, you certainly can. 2" vent is adequate for your situation. Make sure you combine all three vents above flood line or approximately 42" above the floor or higher. 3" main drain is also properly sized pipe to carry your new bathroom.

I am glad you are being resourceful and ask these questions before you start your project.


Milo



This happens all the time in remodeling. Just like Mark advised, two 45 degree bends is the best choice to move the main vent. Milo

Can I vent the toleit, sink and tub on a single 2 inch line.
Sure can! And this is how you do it. (see image). Good luck, Tom