venting question on 2nd floor kitcken
 

I'm building a new farm shop and am installing a kitchen area in a 2nd level space. All that will drain from here is a kitchen sink. The toilet and sink and shower will be directly below on the main floor. My question is this. Do I have to vent this upstairs and down? I will be using a Studor valve as a vent.

If you have a studor vent for the kitchen sink, you're good.

You're just referencing the upstairs sink right, or are you saying you'll use a studor vent for the whole thing?

The whole thing. I would prefer to not put that vent pipe through the attic and roof or outside the new building and then through the roof.

everywhere i have worked you had to have at least one vent the full size (3") through the roof to meet code. but if there is no inspection you can do anything you want. i would run a 3 inch vent up and through the roof from the first floor plumbing.

I think you need to have a vent running outdoors
http://publicecodes.citation.com/ico...017_par009.htm

It doesn't have to be a single 3" vent, but there is a chart (i forget the details/units) that says you need to have an equivalent venting capacity depending on your drain. So if you have a 3" drain (which you will need at least with a toilet), you can not just run a 1.5" vent out the roof. Hopefully someone here will be able to set me straight on this, or i'll post the chart when I get home.