I would like to put a toilet and a pedestal sink in a small room adjacent to my pantry
My pantry has my kitchen sink in it. The sink has a 1.5" vent that goes through the roof and it's waste drains to my main stack. I want to replace the old CI drain pipe with a larger 4" and have that new pipe pick up the new toilet and sink waste as well as the existing kitchen sink waste. Seeing as the kitchen sink and waste stack are already vented, is this enough so that I do not have to add another vent for the powder room. The kitchen vent will be around 10' from the toilet drain, and the main stack is at least 15' from the kitchen drain. What is the easiest way to do this?
Thanks in advance
C/

Sorry but you're going to hafta vent the powder room lavatory. You may not connect to the kitchen drain without venting the lavatory. This vent will have to be run out the roof or revent back to a dry vent. By connecting the powder room lavatory to the toilet drain you are wet venting the toilet through the lav vent. Good luck, Tom