Hi, I am trying to relocate a vanity and convert it from single to double sink. I would like to minimize the space the plumbing takes up inside the cabinet to increase storage, so looking for advice on my plumbing design.

I am using 1 1/2in ABS and, to save cabinet space, I have built a 2x6 chase behind the new vanity so I can run the water and waste lines (I plan to leave the pipes accessible behind the cabinets). I am using vessel sinks, so pretty much only the drain pipe will protrude in the cabinet.

My question is about how to plumb the waste lines:
- can I use a waste arm as an offset from the sink drain towards the chase behind the cabinet, then use a 90deg to connect to on end of an end-type continuous waste kit (runs parallel to wall), pick up the other sink the same way, then connect to a p-trap, then to the waste line?

From the original location, the 1st new sink will be ~5ft away from the original re vent, and the 2nd will be ~8ft away (using a 90deg fitting to go around a corner from the original to the first new sink location, then straight run to second sink - 1/4" per ft slope). I tried to attach photos of some of the part I plan to use.

Regards,
George.

Waste Arm: http://www.plumbingstore.com/images/7inch-sj-wastearm.jpg
Continuous Waste Kit http://www.plumbingstore.com/images/abs-continuous-wastekit-endoutlet.jpg

Hi Ggerodimos

Since your sinks are more than 30" apart from each other most plumbing codes will say that you need a PTRAP for each sink.

Technically, you also run into issues with your vent distance...shouldn't be more than 3-5 feet maximum from the "revent"...;)

May be a good idea to add a studor vent (mechanical vent) here...can vent both sinks if piped properly...the mechanical vent needs to be "readily accessible" so it can be changed in the future should it fail, OK?

Your thoughts now?

Mark

Hi Mark,
I can certainly look into the studor vent and install that. Ayy links or pointers on where to buy and install one?

I will check the exact distance between sink drains, if they are more that 30" I may need advice on how to do this.

Should I add a revent, I can probably fit one in that will keep that distance close. Or do I check with the inpsector?

Thanks,
George.

Hi George

I will always advise you guys to consult your local plumbing inspector if you can as codes differ from city/town/state/country and not just a little, but by quite a lot here. For example, between Maine, New Hampshire, Massachusetts, Rhode Island, Vermont and Connecticut... ALL NEW ENGLAND STATES... we can't agree on almost anything... I swear!

I hope I helped, but if this is being inspected please consult that inspector... he will appreciate that more than you know!

Good luck!

Mark

Hi Mark,
Thanks for the information. I do have permits and will consult the City. Am looking for guidance to see even I even have options so any advice you and the other experts can provide would be great.

I did measure and the sinks are 40" apart, so am not quite sure how to incorporate the second p-trap and accomplish what I need. Any suggestions?

Thanks,
George.

In this case, any advice I have could be LESS THAN HELPFUL if the inspector disagrees with me... ;)

Chat with the inspector... will save you a lot of time/hassle here... I promise!

Agree completely Mark.

Gg, please do let us know what they have to say. Always curioius to hear how inpectors are in other areas. Make sure to wear a big smile and have a pot of coffee on hand. It may or may not help.