Horizontal 3" soil stack look ok?

Good morning, My name is Dan and I just joined the forum and I'm hoping I can get some expert opinions. I have a few questions but I'll start with one that I've researched on here but haven't found what I'm looking for. It concerns my 3" soil stack on the second floor. I've attached a diagram of what I want to do. My question is about the 3' section of 3" pipe that runs horizontal and then goes vertical thru the roof and if it looks ok or do I have to change it? If this doesn't work then my thinking is to use a 3" elbow with a 2" side inlet at the horizontal vertical joint to meet code. My other question is do I have to vent the tub/shower or is the back venting of the Lav good enough?

Thank you.
Dan

The toilet can't enter the 3" horizontal that way. It would skip across the fitting and force water out of the other p-traps.
You need wye fittings in several places.

Thanks Terry, I wasn't sure about that toilet connection. I didn't draw the wyes in on the other two joints, my mistake. So am I to assume the 3" pipe running horizontal after the 3x3x2 wyes is ok? It doesn't have to go vertical at that joint?

Thank you
Dan

DJK265 said:

Thanks Terry, I wasn't sure about that toilet connection. I didn't draw the wyes in on the other two joints, my mistake. So am I to assume the 3" pipe running horizontal after the 3x3x2 wyes is ok? It doesn't have to go vertical at that joint?

Thank you
Dan

Click to expand...

It can stay horizontal there. It would be better without. I don't know why there is a horizontal there, but there must be a reason you drew it that way. It would be nice if you could 45 over from the stack to that wall. A 45 is still considered vertical.

Thanks Terry, The vertical stack is in a 2x6 wall below on the 1st floor, if it goes vertical thru the 2nd floor it would be in the center of the upstairs bath so I had to go horizontal over to the 2x6 bathroom wall. I could move the 2" drain line for the tub & Lav closer to the wall and then elbow vertical after the wye or 45 out of the wye if that makes sense.

Thanks
Dan