My bathroom is pretty small and I only have one. Im interested of seeing if I have any options to reduce the vent pipe size going up through the wall, to get me 6 to 8 extra inches in my bathroom. I know, it doesnt seem like much, but sometimes inches even can make a difference.

Right now I believe the vent is a 4 incher that extends up and is reduced I believe in the attic.

The two top pics are just pics from underneath the bathroom in the basement to give you an idea of the size.

Note the bathroom picture where a large portion of the wall extends out. Im guessing this was done due to the vent size initially. Id really love to get a little extra space here and have my bathroom feel slightly bigger.

What are my best options here?

Any help or ideas are appreciated.

 

That looks like your soil stack. I don't think you can make it any smaller.

 

IMO leave well enough alone. It is what it is.....

 

Plumbing takes up space. Are you prepared for a $5-10'000 remodel and living without a bathroom for a week or two to gain a few more inches of space? Like others have mentioned I'd forget it but if you want to do something I think you are looking at a down to bare studs, complete bathroom re-do.

 

So this vent pipe or soil stack needs to be this big for one toilet/shower?

 

It is probably your main stack. Your main stack basically needs to be the same size as your main drain, so you're stuck with a 3" or 4" stack. Not much you can do about it.

It could possibly be redirected in a closet or something, but it all depends on the layout. Plus, working with cast iron, even if it's just removal, is a lot of work.