Sorry for the double post, for some reason it posted my question as a guest and I couldn't edit it.

Hi all,

Need some expert help. I'm concerned that the previous owners did some plumbing work that may not be installed correctly. Attached are three pictures, 1) a crude diagram of my homes plumbing, 2) a picture of main drain pipe leaving the house, 3) a picture of a the basement bathroom I am trying to remodel (on the other side of the wall from main drain pipe).

So, a couple of things, before starting remodeling, the down stairs toilet would bubble up when toilet was flushed up stairs. The slop sink would fill up when the washing machine emptied.

I'm concerned that the down stairs toilet is discharging into the main drain at the same level it leaves the house. When I pulled the toilet off, I could see raw sewage sitting in the pipe. I'm also concerned that these fixtures have not been vented properly, especially in the basement. The main drain goes horizontally across basement ceiling from one end of the house to the other.

I would like to remodel the bathroom leaving the fixtures where they were and add a sink for a small bar next to the bathroom and tap into the bathroom sink drain line (in red).

Is this setup okay the way it is? If not, what can I do to fix. Will I be okay adding a small sink the way it is diagrammed?


Thanks,
Bryce

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