vent for sink

[mickeyrory]

I'm currently putting a door in where there was a sink. In the attached photos the drain that attached to the sink can be seen. This drain extends diagonally thru the wall that can be seen in the photo. There is also a pipe that goes vertical which I assume is the venting. However, I don't know if it also serves as a drain. When the previous owners finished the basement no bathroom was put in; it was only a single sink. So, in putting this single sink in the basement would there have been any reason to wet vent it? I would like to cut this off and cap it which would be the easiest thing for me to do. However, if it's also used as a drain I am going to have to reroute it. Is there any way, short of cutting the pipe and running water to check if it's a drain, to determine if it's a dry vent?

 

[justin_dewan90]

If you dont plan on using the sink, can you just cut the Wye out and use couplings to tie it back together? You do want to make sure it's not tied to another drain in the house before you cap it.

 

[mickeyrory]

If you dont plan on using the sink, can you just cut the Wye out and use couplings to tie it back together? You do want to make sure it's not tied to another drain in the house before you cap it.

Good idea but I know I can't make the cut on the other side of the wye without cutting out sheetrock. As a last resort that's what I will do. Sure wish I could track that vent back and see where it goes.

 

[justin_dewan90]

Turn on your washer, and drain it. Turn on your kitchen sink and let it drain. Turn on showers and lav sinks. Listen or see if water comes through. That will tell you if something else is tied to that.

 

[mickeyrory]

Turn on your washer, and drain it. Turn on your kitchen sink and let it drain. Turn on showers and lav sinks. Listen or see if water comes through. That will tell you if something else is tied to that.

I'm usually smart enough to do those things. I think I had myself convinced it was just a vent. Kitchen sink drains thru there. I guess by my logic I just wondered why, when prior to finishing the basement and installing a sink, everything in the house went through original drains. My main drain line is practically next to the kitchen sink but when they installed the sink in the finished basement they rerouted the drain in a complete circle and which goes back to the main drain. It must have something to do with using it as a vent for the new drain. Thanks again for your suggestion to cut out the wye and reconnect the drain. I came up with a plan on how to do that without cutting any sheetrock out. Appreciate your help.