Two toilets on same line will this drawing work?

[Codywalsh88]

Option 1: Will flushing toilet 2 cause a siphon or problem with toilet 1?

Option 2: If the above option is a problem, will moving the drain further down the line and to the side of the main drain resolve the siphon issue? In doing so would I need to add another vent for toilet 1?

Thanks!

 

[Codywalsh88]

If it helps... I'm very limited on vertical space under the floor as the drain line runs parallel with the floor joists and can't really drop below them. The typical Double fixture Wye would be too tall to use in my case, that's why I'm trying to figure out how to run it horizontal as shallow as possible. Thanks!

 

[Sponsor]

 

[Reach4]

I am not a plumber. You only want to use a santee to transition from horizontal to vertical.

Ideally use a "combo" or 45s. So run a closet bend to combo in the horizontal. I expect you have plenty of venting there; I don't think you need the extra vent on T#1. Any downstream fixture will need venting.

It seems to me that you could run T#1 to a closet bend, and that would go to a wye located farther up in the drawing. What you drew works too, if it is easier.

I have trouble understanding what is needed with toilet venting. The toilet does not need a vent for the same reasons that other fixtures do. I do think your one vent is going to do a fine job.

A 4x3 spigot x hub street closet elbow takes a 4 inch closet flange, and feeds into a 3 inch pipe.

 

[Codywalsh88]

Thanks Reach4, I'm thinking I just need to switch the end SanTee to a Wye and I should be good