I live on the top floor of a three story condo. I am renovating my kitchen and have run into a problem. I want to remove a wall in my kitchen that the sink is on. There is a 3" vent stack going straight up the middle of the wall I want to remove. Is it ok to re-route the vent stack by adding four 90 degree turns and if so can I use a 2" vent?

Thanks,
Mike

As far as I know, you should have no problems rerouting the vent using four ells.

However, choking down to 2" is NOT a good idea. Even though kitchen sinks can be vented using 2" pipes, there is another factor to consider: most (if not all) codes require at least one 3" stack in the house, and very often plumbers will make that the kitchen stack (especially since food disposers became popular). So unless you're absolutely sure that your plumber was not counting on the kitchen vent being [part of] your 3" stack, you shouldn't choke it down to 2".

Cheers,
Moishe

Hi Mike,

Moishe is bang on with his answer. Plumbing codes call for one 3 or 4" vent in a new house. We used to install this vent in a bathroom but when garbage disposals became popular we were forced to increase the size4 of kitcken drain lines from 2 to 3". So we just extended them out the roof for the main vent. While choking the vent down to 2" would work as a vent it would be against code to do so. You may have as many bends as you wish in a vent providing that they are upstream from the drainage section, just remember to invert any tees or wyes and slope back to the drain. Good luck, Tom