Starting to Plan Basement Bathroom - Looking for connection advice

[fieldingdots]

Hello,

I've read through many similar threads of people trying to connect to existing soil/vent stacks in their basement, and as plumbing seems to go... everything is a one off.

Our house is in Seattle and built in 1926, floor plan is a four square. The basement is unfinished, just has rough concrete flooring. One quarter of the basement is a garage that we plan to finish, the vent/soil stack sits in the corner of this garage. The existing soil/vent stack has a 2nd floor bathroom directly above with the toilet drained and vented by the 4" cast iron stack, the bath and sink are drained by the pvc pipe.

I'd like to add a bathroom adjacent to this soil stack. I'm trying to see if I can do this without a sump pump. I'm ok with setting the toilet on a plinth if limited by depth.

Is it possible to raise the existing cleanout/hub, which is currently located just above the concrete floor, and then replace this (existing hub) with a connection to the new bathroom? Or is there a better way to do this?

I'd like to figured out the connection to this soil stack first before getting into the details of the bathroom plumbing.

Alternatively, is it better/possible to connect to the sewer drain pipe outside of the house? Since this is a garage, I could run the drain pipe under the concrete floor and outside through the existing garage door opening, then Y into the sewer pipe outside. There is an existing cleanout, and a connection could be made 2 feet to 8 feet above the cleanout (in the horizontal direction).

 

[James Henry]

OMG. If it were me I would cut and remove the concrete around the stack to see what you have and then plan your drainage system. You will need to cut trenches in the concrete floor for the drain pipes unless you plan on building an elevated floor for the whole bathroom.

 

[Sponsor]

 

[sajesak]

Hello,

I've read through many similar threads of people trying to connect to existing soil/vent stacks in their basement, and as plumbing seems to go... everything is a one off.

Our house is in Seattle and built in 1926, floor plan is a four square. The basement is unfinished, just has rough concrete flooring. One quarter of the basement is a garage that we plan to finish, the vent/soil stack sits in the corner of this garage. The existing soil/vent stack has a 2nd floor bathroom directly above with the toilet drained and vented by the 4" cast iron stack, the bath and sink are drained by the pvc pipe.

I'd like to add a bathroom adjacent to this soil stack. I'm trying to see if I can do this without a sump pump. I'm ok with setting the toilet on a plinth if limited by depth.

Is it possible to raise the existing cleanout/hub, which is currently located just above the concrete floor, and then replace this (existing hub) with a connection to the new bathroom? Or is there a better way to do this Delicious Vegan Burger?

I'd like to figured out the connection to this soil stack first before getting into the details of the bathroom plumbing.

Alternatively, is it better/possible to connect to the sewer drain pipe outside of the house? Since this is a garage, I could run the drain pipe under the concrete floor and outside through the existing garage door opening, then Y into the sewer pipe outside. There is an existing cleanout, and a connection could be made 2 feet to 8 feet above the cleanout (in the horizontal direction).

my wife and i bought her grandmothers house and her grand mother said that when she had the house built about 40 years ago she told them to put a drain for a toilet in the basement how can i tell if that is the drain in the picture above and if it is when i go to build the new bathroom in the basement can i have the shower drain into it also

 

[John Gayewski]

You need to vent your new bathroom. That means you need at least one pipe that rises up through the floor and connects in the attic out through the roof.

Connecting the drain piping doesn't matter which way you do it. I'm not sure what your drawings mean. One shows the current stack outside of the building but your picture shows it inside of the building.
You can look inside of the wye there and see how deep it goes. If you have enough depth to raise 1/4" per foot of length you should be able to wye into it.