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mkmohn
adding second toilet to 3 inch drain

I would like to add a second toilet, in a new bathroom, on the back side of our main second floor bathroom. The main bath toilet currently drains into a 3 inch pvc pipe. Can I simply add the second toilet down the line from the main bath toilet? Understanding, of course that the venting would have to be proper. I read somewhere, that, if you are adding a second toilet you have to increase the size of the drain from that toilet on.

johnjh2o
Re: adding second toilet to 3 inch drain

3" is OK for two toilets.

Fencepost
Re: adding second toilet to 3 inch drain

When I was plumbing 15 years ago, you could install up to three toilets on a 3" drain.

johnjh2o
Re: adding second toilet to 3 inch drain
Fencepost wrote:

When I was plumbing 15 years ago, you could install up to three toilets on a 3" drain.

You're correct but before the low flush toilets you were only allowed two toilets on 3".

mkmohn
Re: adding second toilet to 3 inch drain

Does it matter that there will also be a sink, tub and shower on the same line?

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