Laundry room utility sink

[Rob Keeling]

I would like to add a utility sink beside the washing machine. I’ve read plenty of threads from numerous sites and this in my opinion is the best place to ask my question. I’ve exposed the builders washing machine drain and water line. Question is...... what’s the simplest and best way to add the sink? I’ve attached a pic. Thanks everyone.

 

[WorthFlorida]

A double fixture tee. One side washer the other side the sink. Do not use a double sani-tee,

 

[Sponsor]

 

[wwhitney]

A double wye or combo would require separately venting each side before the double fitting, which would entail a lot of changes.

The details of how to do this vary significantly between the two main US codes. Not sure what the Canadian code allows/requires. But simplest and somewhat likely to be code compliant is to add another sanitary tee above the washing machine sanitary tee, for a short vertical wet vent. The question is whether you can install it low enough to work with the trap outlet of your utility sink. Utility sinks are often quite deep and so need a low enough sanitary tee.

Cheers, Wayne

 

[Rob Keeling]

A double wye or combo would require separately venting each side before the double fitting, which would entail a lot of changes.

The details of how to do this vary significantly between the two main US codes. Not sure what the Canadian code allows/requires. But simplest and somewhat likely to be code compliant is to add another sanitary tee above the washing machine sanitary tee, for a short vertical wet vent. The question is whether you can install it low enough to work with the trap outlet of your utility sink. Utility sinks are often quite deep and so need a low enough sanitary tee.

Cheers, Wayne

Thanks for the information Wayne.
Another question for you. This will give me some clarity.
The sanitary tee from the washing machine is 2” down to 1 1/2” after the trap. If I’m tying into this system is it better to use a sanitary tee before the trap or on the 1 1/2” side after the trap? Thanks again Wayne

 

[wwhitney]

Ah, I see that now, you have a 2" standpipe going to a reducing p-trap, so that everything after the p-trap is 1-1/2". Seems unusual, particularly for new construction, but maybe that is something that Canada allows, I don't know.

Anyway, you can't double trap a fixture, so if you install a normal laundry sink with trap, you'd add a 1-1/2" san-tee above the existing san-tee, not on the standpipe.

[In the US, IPC does have a newish and somewhat unusual allowable detail for a laundry sink and a standpipe to share a single trap, and it involves a san-tee on the standpipe with no trap at the laundry sink. But unless you find that the Canadian code explicitly allows that detail, don't use it.]

Cheers,
Wayne

 

[Rob Keeling]

Ah, I see that now, you have a 2" standpipe going to a reducing p-trap, so that everything after the p-trap is 1-1/2". Seems unusual, particularly for new construction, but maybe that is something that Canada allows, I don't know.

Anyway, you can't double trap a fixture, so if you install a normal laundry sink with trap, you'd add a 1-1/2" san-tee above the existing san-tee, not on the standpipe.

[In the US, IPC does have a newish and somewhat unusual allowable detail for a laundry sink and a standpipe to share a single trap, and it involves a san-tee on the standpipe with no trap at the laundry sink. But unless you find that the Canadian code explicitly allows that detail, don't use it.]

Cheers,
Wayne

Thanks Wayne. You’ve been very helpful. This set up is from 2003 construction. Codes have changed for sure. I have a couple options now and I guess I’ll just have to choose.