We have a first-floor shower we have removed and want to use the drain and supply lines for a bar sink on the other side of the adjacent wall. We are on a crawl space, have removed the fiberglass shower, capped the supply lines, and have access to the shower drain. The shower drain trap is just below the floor and the old flange connection is approximately 18" from the wall where we want to install the bar sink. Should we use an AAV on the bar sink and run the drain line to the existing shower drain and leave the shower drain trap in place? Any other suggestions for proper venting?

45482

Yes, you can use old shower plumbing for new bar sink. Water supplies are no problem - just extend them where you want them and install new angles stops (valves). As far as drain goes - cut the trap and cap the pipe. Now, install new Sanitary Tee onto existing shower vent and run horizontal "dirt arm" towards your new sink location. There, install new 1 1/2" trap under new sink.

Back to you. Milo