need a little help designing the plumbing for this toilet add on

Old 03-27-21, 09:10 AM
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Location: Ontario, Canada
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need a little help designing the plumbing for this toilet add on

Hey Gang.

I wanted to add a toilet in my basement. It is finished and the room I want to add it in, has the main stack in the corner I can access. I rather not rip up the floor to add one, so I was looking online and can get a rear exit (discharged) toilet which mounts to the floor which looks like it will work perfect for my needs.

There is an existing sink already plumbed down there so I just wanted to change up the drain size and hopefully connect off the stack in the pics I attached.

Can this be done? am I missing a vent? thanks

Old 03-27-21, 02:45 PM
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You'll need a vent for the toilet. It needs to be 2" and not part of another drain - code doesn't allow wet-venting between floors. So you'll need to run a 2" vent up through the roof from the toilet to remain code-compliant.

Some areas will allow an AAV, but an atmospheric vent is preferred.

Also, the first-floor venting seems odd, but that's obviously out of the scope of your question/project.

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