View Full Version : Question about plumbing a wet bar sink in basement

06-06-2012, 08:30 AM
I am planning on adding a wet bar sink (with garbage disposal and dishwasher) during my basement finishing project. The location of the wet bar will be on the same wall as the stubbed bathroom group (sink, toilet, shower). I would like to connect the wet bar sink drain to the bathroom sink drain and also connect the wet bar sink vent to the bathroom group vent. Could someone look at the attached drawing and tell me if there are any issues with my plan. I plan on sloping the wet bar sink drain toward the bathroom sink drain 1/4" every foot and just putting a slight slope on the wet bar sink vent toward the drain it serves. The red lines indicate the added wet bar sink drain and vent and the black lines are the existing stubbed bathroom group drains and vents. Thanks for the help.


Tom Sawyer
06-06-2012, 08:46 AM
I don't see any issues provided you maintain proper slope of the new drain, use a sanitary tee at the connection below the bathroom sink and provide a clean-out below that. If you are on a septic tank the new code says that if you use a garbage disposer the size of your septic tank should be increased by 50%

06-06-2012, 08:52 AM
I don't see any pipe sizes. If your using a disposal the line to the bar sink must be 2".


06-06-2012, 09:15 AM
Thanks for the quick reply guys. I am not on a septic tank (I am on county/city sewer system). I am sorry to sound ignorent, but what is the need for adding a clean out below the connection at the bathroom sink? There is no clean out in the existing stubbed work, but there are clean outs at the main stacks and in the basement floor (the basement floor clean out is really close to where I am putting the wet bar sink - almost directing below it). I am a little concerned that I will not have enough space to put the clean out below the connection at the bathroom sink and still maintain a proper slope. Due to the distance from the wet bar sink drain to the bathroom sink drain, I will need to slope the pipe about 5" toward the bathroom sink drain. I may have enough room, but will have to do some measuring to be sure. I forgot to list the pipe sizes. I think the existing drain and vent is 2" (I am at work and will look to be sure tonight) so I plan to use 2" for the additional drain and vent. Thanks again for the help.

06-06-2012, 09:27 AM
The vent can be 1-1/2"