New Sink Installation

[Brian]

I am remodelling my second-floor bathroom and want to add a second sink. The existing sink has a 1.5" drain and vent. The vent goes directly up through the roof and the drain drops down into the floor space and then runs horizontally for a while before going through the next wall. I'm assuming it ties directly into the main waste stack.

So, I am wondering what the options are for draining and venting the new sink. Here's what I'm thinking...

New Drain: If I'm interpreting the Uniform Plumbing Code correctly, a 1.5" horizontal drain can supply 1 dfu. Does this rule out connecting the new sink drain to the existing sink drain? If I can't connect the new drain to the existing sink drain, can i run a new drain line for the new sink and tie it into a horizontal run of a 2" drain line from the shower? The UPC states a 2" horizontal drain can supply 8 dfu, so I would think that would be sufficient?

New Vent: I am assuming that I can run a vent pipe for the new sink 6" or more above the rim of the sink rim and then tie it over to the existing vent pipe that runs up through the roof. The UPC states that a 1.5" vertical vent can supply 8 dfu which would be plenty sufficient.

Other than simple under sink plumbing I don't have much experience so any advice is appreciated. I have done a good deal of research trying to figure out what is allowed, but I'd like to get some reassurance/corrections. Thanks in advance!

-Brian

 

[Nailer341]

Are you just adding in a sink to the same counter? Like a his and hers sinks?
If this is the case, let us know the distance between them, and you may be able to "dirty arm" the new one in and utilize the same vent.

 

[Brian]

Yes, there will be two sinks in the same vanity. The new sink drain will be roughly 45" from the existing drain and vent.

 

[dunriteplumbing]

are you having an inspector coming to check your work? if so have him come out, ask him what to do. he or she is the one to talk to. if no inspector just tie into the existing drain line with a sanitary t ,run inch and a half pvc over to the new sink and if you want to get fancy put a air admittance valve in.