View Full Version : Utility sink and washer - is Design Correct

10-18-2010, 02:44 AM

I first want to start off my question by letting you know that I am in a suburb just outside Chicago, but still in Cook County. The Village i live in follows the IPC 2009 Code. I am trying to gain some space to perform a bathroom model next year for my 1950's raised ranch home. I am gaining some extra space by getting a new front loading stackable washer and dryer and moving them from an existing hall wall to a utility room. I want to make sure i am putting in the proper drain pipe setup, considering the space constraints i have. I am posting a very crude sketch of the main wet wall in this basement utility room, and the side wall the washer\dryer will be moving to. I am also having a new utility sink installed. All of this work is going to be done by myself, in fact i have already put things in place. (my building codes for my area states that for residental any general plumbing work costing less than $250 needs no permit). I am concerned that i might have installed everything putting an air admittance valve in the wrong location. (I am concerned that the existing drain pipe i branched off of won't have enough back pressure to drain the washer)

Thanks in advance for any help you can lead my way!

10-18-2010, 06:04 AM
I'm not a plumber, but I'll try to get you started:

- washer needs a 2" trap and standpipe. The 1.5" is too small

- the washer line needs to then dump into a 3" or larger vertical or horizontal branch (this is in 2006 IPC and should also be in the 2009 version)

- reducing the pipe size in the direction of flow (the 1.5" to the 1.25" reducer in the pic) is not a good idea. The 1.25" is also really too small for the washer

- the current setup doesn't properly vent the sink. When the washer runs, it'll pull the water out of the sink trap

Probably the easiest solution is to just put the washer hose into the utility sink. Since the utility has some storage capacity, the line does not have to be 2". We'll see what the pros think.

10-18-2010, 09:55 AM
The entire portion of plastic should come out.
It look like you have a fixture on the other side of the wall that is vented on the left.
That should have been left alone, and a new 2" line from farther back at the least.
Each trap needs a vent, not one vent for three fixtures.
The washer is undersized, and the laundry trap, which can have a 1.5" trap, but must be 2" after the vent.
The washer needs a 2" p-trap and stand pipe.
The fixture on the other side of the wall needs to be returned to what it was, it had a vent before, but now that you are running a washer and laundry tray by it, it will now siphon the trap everytime they run.

10-18-2010, 11:06 AM
Thanks for the response to my question and diagrams. I had a feeling that the pipe and vents used was under sized. My space is extremely limited for the location i can run pipes. I have existing walls, electrical conduit\ and service, and water lines that are in the way. Just to make sure I am understanding things correctly. I should run a new 2" drain pipe and 1.5" vent for the washer that will come off the existing vertical 3" drain pipe and 1.5" vent pipe? I should also run another separate 1-1/2" drain and 1-1/2" vent off the vertical 3" pipe for the utility sink? I should have the 1.25" coper pipe be a drain just for the bathroom sink (adding the utility sink and washer drain is too much for one 1.25" pipe drain). Would the daigram below work for adding the utility sink and washer stand? The new washer i am installing is HE and uses 50% less water than my old washer. (old washer's drain is shown on diagram)


Thanks again for any help you can give me!

10-18-2010, 04:23 PM
The highlighted area in the sketch above is where any new pipe and fittings would be installed as compared to the original drawings i uploaded

10-19-2010, 08:34 AM
If someone can please let me know if the last sketch i attached to this post is correct. I have a new washer and dryer coming tomorrow and i have to get everything taken out that is wrong and the new installed before they come. Thanks!