Basement washing machine vent question

[handywill]

Hello,
I am finishing my basement and have a question about how to vent a washer. I have a washer going in about 12 feet from the main soil stack (cast iron, goes into floor, not “hung”), which I had a plumber put in a place that I can connect to with 2” PVC a while ago. The stack has various other things connected to it, including a toilet, sink, and a 3 inch line from an addition we had put on our house (which has its own vents). Next to the 4” stack, there is a smaller cast iron pipe that looks to be 1 1/2”, with only a slop sink going into it, and possibly more fixtures draining into it above. My question is could I tie into this 1 1/2” pipe (above where the sink drains into it) for an auxiliary vent/revent for the washer (red option in drawing)? The only problem I see is that the slop sink gurgles when it drains, which could be a venting issue. Another option would be to vent into the main stack, because that is obviously what the toilet is vented with, which works fine (blue option in drawing). The last (unfavorable) option is to use a Studor vent, which I’ve read don’t always work with washing machines (black option in drawing). Please see the attached drawing (and note that none of the fittings or slope of the pipes are correct at all, the drawing is just for a basic idea). Thank you!

Image link: https://ibb.co/F7GbLgf

 

[Reach4]

The last (unfavorable) option is to use a Studor vent, which I’ve read don’t always work with washing machines (black option in drawing). Please see the attached drawing. Thank you!

I looked. Your options all seem valid, but your vent lines must be able to drain any moisture downhill. IPC is more tolerant in that you could drain either way. I figure you were taking artistic licence in drawing option 1. ;-) Option 1 vents the slop sink and the standpipe with a 1-1/2 inch vent. That is plenty OK with IPC.

That fitting where the vent joins the drain should be pointed the other way. In UPC, that fitting would be a combo, but under IPC it could be a combo or even a santee on its back.

 

[Sponsor]

 

[handywill]

I looked. Your options all seem valid, but your vent lines must be able to drain any moisture downhill. IPC is more tolerant in that you could drain either way. I figure you were taking artistic licence in drawing option 1. ;-) Option 1 vents the slop sink and the standpipe with a 1-1/2 inch vent. That is plenty OK with IPC.

That fitting where the vent joins the drain should be pointed the other way. In UPC, that fitting would be a combo, but under IPC it could be a combo or even a santee on its back.

Thank you much! I know none of the fittings in the drawing are correct (santee, wye, tee, etc), and the slope of the pipes aren’t shown either; I was just trying to get the basic point across. I was most definitely not doing anything artistic in any of the options ;-).

 

[handywill]

Hello,
I am finishing my basement and have a question about how to vent a washer. I have a washer going in about 12 feet from the main soil stack (cast iron, goes into floor, not “hung”), which I had a plumber put in a place that I can connect to with 2” PVC a while ago. The stack has various other things connected to it, including a toilet, sink, and a 3 inch line from an addition we had put on our house (which has its own vents). Next to the 4” stack, there is a smaller cast iron pipe that looks to be 1 1/2”, with only a slop sink going into it, and possibly more fixtures draining into it above. My question is could I tie into this 1 1/2” pipe (above where the sink drains into it) for an auxiliary vent/revent for the washer (red option in drawing)? The only problem I see is that the slop sink gurgles when it drains, which could be a venting issue. Another option would be to vent into the main stack, because that is obviously what the toilet is vented with, which works fine (blue option in drawing). The last (unfavorable) option is to use a Studor vent, which I’ve read don’t always work with washing machines (black option in drawing). Please see the attached drawing (and note that none of the fittings or slope of the pipes are correct at all, the drawing is just for a basic idea). Thank you!

Image link: https://ibb.co/F7GbLgf

I was thinking, and another possible option would be to keep it super simple and have no trap where the washer is and just run 2” PVC dumping into the slop sink. It wouldn’t be the most elegant, but it wouldn’t require any venting at all. The sink has two basins, so we would still be able to use it while the washer is going.