double sink versus single sink

[jaydub2010]

was looking to expand my bathroom and get a bigger vanity with a double sink. Going to be taking down the wall and expose the plumbing and venting. When plumbing for a double sink do I need to have more than just the 1-1/2" ABS? for the drains? I imaging that I can have 1-1/2" from sink to the wall, but then does it need to be 2" from there to main stack?

[hj]

It SHOULD be 2" from the connection, (and that connection has specific requirements for how you do it), for the two sinks to the main stack. Until you open the wall, there is no way you can tell HOW you are going to do it, and in some cases it requires a major repiping to do it correctly.

[jaydub2010]

Thanks HJ, when you say 2" from the "connection" are you saying the P-trap under each sink should be 2" or the "connection " inside the wall. Haven't opened it up yet so I don't know what is there. My assumption is that it will be 1-1/2" but we'll see, its 1982 construction - so I'm fairly certain that it will be ABS at least and not Galv.