Adding a Toilet Upstairs

[mlennon]

Hello,
This is my first post here so bear with me...
I have a small cape cod which is a slab on grade in Eastern PA. I currently have a 3" drain line sticking out inside my wall between the kitchen and bath that drains the sinks on either side. the toilet and tub downstairs go underground and tie into this line. I also have another 3" Clean Out about 6" away sticking up with a cap soldered on. I would like to use this 3" CO line as a stack for a new toilet upstairs. there are 2 x 8 joists up above. Do you think using this line is feasible? I also wanted to know about locating the toilet away from this drain line. Is there any way I can run the 3" line perpendicular to the 2 x 8's? I understand this is more of a structural question, but I'll throw it out there.
Thanks for your help.

[pushkins]

No matter what you do you must still have a cleanout (probably where it is).
Does the 3" stack between the toilet and kitchen go straight up the wall and exit out the roof as a vent ?
You mentioned that the cleanout cap is "soldered" on, what is the waste line made of ?
You are going to run into big problems if you want to run this new 3" pipe perpendicular to any of the upper level floor joists, cutting a 3" hole in any 2x8 joist is a big No No and will lead to structural failure.

[mlennon]

The 3" stack does go up and out through the roof. It reduces down to a 1.5" line and vents out the roof. I am not sure what the 3" lines are made of. I think they are copper underground and they are lead above ground. Everything above ground will be getting replaced with PVC. Have you every heard of anyone getting around running 3" perpendicular to the 2" x 8" joists by say doubling them up (sistering) or putting blocking between or anything? I currently have the entire ceiling out and I really don't want to trench into the floor and add another soil stack to the home.

[pushkins]

No, you cannot sister on any extra joists as these too will need to have a 3 +" hole in them.
The only thing you could do is to run the waste line down between the floor joists and then cross through them where you need to get to the new toilet, if this is only one or two floor joists then you could cut the floor joists add "headers" and create a pass through.

[LazyPup]

The maximum diameter hole permitted by code in a 2x8 joist is 2-1/8"

Joists may not be notched in the center 1/3 of their overall span.

In the outer 1/3 of the span you may notch the top of a joist a maximum of 1-1/2"

No notches permitted on the underside of a joist except at the very end, and when notching at the end the maximum notch in a 2x8 is 1-7/8"