I want to move my sink in my kitchen to an adjacent wall, can I run the vent just to the top of my 1st story roof? Is there a height requirement? I live in Hawaii.
Thanks

I don't know what plumbing codes are where you are but you can close the vent off if there is no other fixture tied into the vent. Move your sink then add a cpvc air vent that sits under sink, it ties off the p-trap. That's one way to do it.

If I understand your question correctly, it sounds like your roof has two levels and you want to know if you can run the vent pipe out through the first story roof. You should be able to do that. But like Celer said, seal up the old vent and go to your town hall and ask about local building codes. Depending on the municipality, they may require you to place the new vent pipe a certain distance from windows.

Well, I have used the old vent. Plus, put in a syphon vent above the drain under the sink.
So I have a drain in new location w/cpvc vent and a 2" pipe that runs about 3.5 ft to 90 degree bend, then runs until it hits main (original vent) at about 18 inches and on to original drain in floor another 12 inches. All at a 1/4" per foot grade.