Hey guys,
Im a DIYer and I'm remodeling my kitchen. The current sink is on an inner wall that has the bathroom on the other side of it, and the main drain runs right up through that wall. My intentions are to move the sink from that area about 12 feet to the other side of the kitchen. My questions are, 1) can I extend to the main that far as long as there is a downward slope to it?
2)Do I need to have a new venting put in.

Thanks in advance..

Yes you can but how are you planning to vent the new sink? Avoid 90s in the drain, go with several 45s if you need to. Drop at least 1/4" per foot.

Well I am moving the sink to a corner of the kitchen that that has a window on each wall 1ft from the corner. It's a capecod and the kitchen doesn't have a second fl area over it. My plan would be to cut a hole directly in from the roof and in that corner. Cut open the wall and stub out my connections and continue into the basement and extend from there into the drain.
Is there a rule of thumb as far as the slopeing is concerned?

Sorry didn't really answer your question, once I have it in the basement I'm going to use a 45. But the rest will be straight up through the roof.

You asked about slope. Follow Bals advice and give your run 1/4" of fall to the foot. Good luck, Tom

Yeah I caught that a little while ago. Thanks