First let me say this plumbing forum is very informative! Now also let me say that I am not well versed in plumbing lingo so hopefully I will be able to ask my question correctly.

We plan to remodel our master bath. Currently our bathroom has a separate room for the lavatory, toilet, and shower. The bathtub is on the other side of the wall. The shower and toilet go into a main stack. Our bathtub goes into it's own stack. The bathtub stack goes straight up from the basement through the wall that separates the shower from bathtub. We would like to move that wall so we can make the shower larger.

Can we take the stack at a 45 degree angle for let's say 1 foot and then have it go straight and up to the roof? An add on question - if we can do that, can we then also take that stack and 45 degree it in the attic and back into the old stack that goes through the roof so we don't have to put another pipe through the roof?

I hope I asked this correctly. Thank you in advance for any advice you can give.

If it is just the vent, it shouldn't be a problem. Two 45's are not going to add much restriction at all.

Yes to all your questions. You may offset the vent to give you more room for your shower and then re offset back to tie back into the roof vent. Good luck, Tom