Sink & Washer sharing same drain pipe - help!

I did some reading/youtube before proceeding with plumbing to add a laundry sink to my basement (above ground/walkout) next to the washer.

How can I correct the plumbing in the photo(s)?

As you can see from the photos, the I tapped into the 2" drain with a fernco tee on the left, then 2 x45 elbows to realign the drain, followed by a sanitary tee (reading this forum I know believe this is a code violation, even though there is no leak when the HE washer drains), then continuance onto the washer weir/trap. The distance from the fernco tee to the center of the washer trap is 3.5", and there is a 1.25" grade/slope.

I did not want to nor attempted to remove the 2x45elbows below the fernco tee since I feared complicating anything mistake.

The studs are not weight bearing (and are against a cast concrete walkout basement wall anchored horizontally with 3.5" tapcoon screws).

The city plumbing code refers to the international code.



Thank you
Marlon - Baltimore, MD

I would have run 2 separate 2" drain lines to the vertical stack, with the sink drain cut in over the top of the washer drain. The washer must drain into a proper standpipe or into a laundry sink.

If there are any fixtures draining into that stack from the floors above, it will NOT be a code approved installation.

Thanks for the quick response. There are no fixtures draining into the stack from above and the vent pipes remove were clean and dry despite being there for 14 years.

The kitchen and second floor bathroom sinks drain into a 3" sewer stack on the opposite side of the house.

Can I simply cap off the sanitary tee to the sink with a fernco instead of cutting it out? Then I can measure and see if another sanitary tee will fit in above the fernco (the problem I anticipate is the height of the second tee being too high for a 13" deep sink in a 34.5 sink base).

Now I wished I had paid more attention to my dad (licensed plumber) who paid for my engineering degree...

I don't think your height will work. Check that pitch too, as it looks too steep, which will cause the trap to siphon. The max distance between vent and trap is based on 1/4" per foot.

The pitch is about 1.25" for a length of 3.5'.

You have room there to cut the pipe close to the floor.
Coming off near the floor will be needed.

If a trap is properly vented, there is no such thing as too much slope! It appears that the WM standpipe is too far from the vent, and the sink would be okay if it didn't have the WM flow going by it for venting.