Kitchen & bathroom sharing drain.

[James Ghelarducci]

I'm remodeling my house and was planning to move my kitchen sink to a wall that has a bathroom sink on the other side. I'm going to use a plumber eventually, but I wanted to know how much can be shared between the two sinks. I'm hoping to avoid the need for the plumber to dig up concrete to put a new and separate drain line in. My question is, can they share a drain line and share hot/cold water lines? I am planning on using a one drain kitchen sink.

 

[Terry]

Since the 70's most lavs have been 1.5" and kitchen sinks 2.0" on the waste lines before the traps.
Lav can get by with a 1.25" trap which is rate now. Most of us use a 1.5" trap that reduces at the 1.25" tailpiece for the lav drain.
Kitchen sinks use a 1.5" trap for their sink baskets and disposers.

In the 60's kitchens were done with 1.5" and I have lived in homes with that, and it will work. Not code though.
Have you opened the wall and looked at what you have yet?

 

[Sponsor]

 

[James Ghelarducci]

House is 1975.
I just took a look under each sink, but did not open up the wall yet. The existing kitchen sink is in the middle of the room, so it goes straight into the concrete. That drain looks like 3" cast Iron. Not sure what the inner diameter is. The bathroom sink, where I want to the kitchen sink to to meet up with is probably 1.25" from the pipes I can see in the cabinet.. So, looks like we are going to be digging up some concrete. Hopefully the Kitchen sink Cast Iron under the concrete leads straight to the bathroom where the header is hopefully located. The plumber can then dig up and use the existing line for the kitchen sink?

 

[hary1971]

Sink vent serves both sink and toilet the configuration depends upon your bathroom layout and the direction of the floor joists. but connect the sink drain to the toilet drain within six feet of the toilet, if possible.