I am running a 2" drain pipe from a shower drain to a 4" cast iron toilet drain. Does the wye have to be at least 45 degrees vertical? Or is horizontal ok?
There was no room to connect it to the vent stack. I had 3 plumbers come out for bids. 2 of them said they would do it the way it is shown. Strangely, they never got back to me with the cost.