I am turning my previous kitchen into a mud room and adding a washer and dryer. I'm running into a few issues figuring out how to run the plumbing and could use some advice.

Here is a picture of how the sink was previously plumbed.



Here are the issues I'm having.

- The plumbing is on an exterior wall farmed with 2x4s.
- The stud cavity that main line / vent is in is small
- The way the sink was previously plumbed took some major notches out of the studs already

My plan is to run 2" PVC up from the basement below. I then plan to build a wall out vertically from this wall to house the standpipe and p-trap for the washing machine to keep it from freezing.

I would like to do something like this with the washing machine trap facing forward instead of to the side.



Unfortunately as you can see in the first picture this will require me to hack up the king stud of the window even more that it already is.

The image below would also be an option. I realize it's a wet vent but I could use the existing notches and that seems better than hacking another hole in the 2x4s.




Any thoughts on what my best approach would be? Fixture venting the washer line doesn't seem like it will work either because due to space I need to keep the stand pipe close to the exterior wall. It also seems like the current layout with the dual drains was already wet vented anyway?



Edited 1 times.

keep your laundry trap full size 2 inch and you should be fine..

Packy, thanks for the reply. I'm assuming you mean I should be fine wet venting the utility sink assuming that I keep the washer drain and p-trap 2"? That was my plan even though the third image shows 1 1/2".



Edited 2 times.

you are wet venting the laundry with the utility sink. so, as long as the vent remains full size 2 inch an the san tees are closer than 10 inches apart, you are good to go.
you need a cleanout in there as well. above the top of the washing machine (in the vent ) is fine..

The tee for the sink needs to be above the tee for the washer drain trap. The stand pipe out of the trap needs to be at least 24" tall ( 2015 UPC Code ). The opening into the standpipe needs to be at least 35" from the floor.

804.1 of the 2015 UPC states standpipe shall be 18" to 30".

Packy,

Regarding the cleanout. If I have one directly below these drains in the basement is that sufficient or do I need to have one on this floor as well?

I would put a clean out in because these are two of the most likely drains in the house to get clogged IMHO. Also, the photo may lie but make sure you have grade on those horizontal lines to the trap if you plumb it that way. Copper is smoother than Cast Iron and a little less likely to build up debris...a little.



Edited 1 times.

cleanout below covers the code.