Fitting a utility sink

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by Steve T, Jul 29, 2014.

  1. Steve T

    Steve T New Member

    Messages:
    4
    Howdy folks! I'm hoping for help and ideas to help me add a utility sink in a cramped space - in particular, I want to make sure I get the DWV plumbing right.

    I have a tiny laundry room in the back corner of my garage. I have an over/under washer/dryer unit now, and am preparing to add a utility sink on either side of the washer. All the plumbing is against an exterior foundation wall. Unfortunately this room also houses my water heater and air handler; and is barely deep enough for the W/D unit as it is. I need the washer backed as close to the wall as possible, which means there's no room to cross drain and vent lines over each other, or over the rigid dryer duct.

    I've sketched up two configurations that I am considering for the sink. The first would locate the sink to the left of the W/D, draining into the existing horizontal branch via a combo wye. Is this a valid approach? The drawback is that I'd have to elevate the sink basin about 6" above its normal height to provide the necessary fall. Also it will not be a straight-back shot; I'll probably need a pair of 45's between the basin and the wall. But the length should be below 24". I don't mind the basin height too much, although this will rule out use of the sink as a urinal. Perhaps also a plus?

    Option B is to put the sink on the right side of the W/D. Here I believe it makes sense to drain the sink directly into the W/D standpipe without its own trap. Basically, the standpipe will be a part of the sink basin, sharing a single trap. I don't immediately see a reason why this won't work -- or am I overlooking something? If you're wondering, no, I don't really want to drain the washer into the sink. I like it having its own secured connection to the standpipe. Aside from possible functional defects I've overlooked, the main drawbacks for this approach are that the sink will partially impede access to the water heater, that I'll have to move the 220V outlet, and that I'll have to reroute two gas lines and the furnace flue so you can use the sink without hitting your head! The later items were clearly installed by morons and can be easily routed out of the way.

    With that said, I'd really appreciate any feedback on either approach, or alternate suggestions!


    Plumbing.png
  2. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,032
    Location:
    Cave Creek, Arizona
    I don't feel like making a drawing, and a description may be hard to follow, but I will try. Remove the sanitary tee from the vertical line and replace it with a Y with the side branch going horizontal. Attach a "street sanitary T", into the top of the first Y with its inlet facing out for the sink's trap. Then continue the line, (it can be 1 1/2"), upwards on a 45 and connect it to the washer's vent at a point 42" above the floor. Take the sink off the cement blocks.
  3. Steve T

    Steve T New Member

    Messages:
    4
    Thank you for the help. I'm not sure I followed your description, though. The attached image is my best attempt at interpretation. I like how the sink connection is lower, but I'm not sure the vent line makes sense. Could you provide another pointer or two? Thanks! plumbing2.png
  4. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,032
    Location:
    Cave Creek, Arizona
    turn the second Y 90 degrees so it points to the right. Connect the washer back to that opening. Insert a street sanitary tee into the TOP of that Y with the opening pointing out. If it comes out too high, remove the cleanout tee, put the new Y there and move the cleanout above the Y.
  5. Steve T

    Steve T New Member

    Messages:
    4
    Thanks again. I think I'll be able to fit things together as you described... At least within 1/2 on inch of uncertainty. Many of these fittings are not stocked at local supply houses, so I'll have to order online and measure upon receipt to confirm the plan. Now that I am cutting into the vertical drain pipe to relocate the existing cleanout, I have a couple more questions:

    1. What kind of seal / bushing will I need to connect my new 2-inch "stack" to the iron hub at floor level? The existing connection seems to be some sort of rubber bushing; I'm not familiar with this type of plumbing. I've attached a photo.

    2. Are unions permitted for DWV plumbing? I won't have the clearance / slop to socket-weld the complete vertical assembly in place. If not, what is the preferred approach for zero-clearance assembly with DWV?

    3. Can I mix in standard schedule 40 or schedule 80 PVC fittings in a DWV system? Or must all fittings be the shallow-socket thin-wall type? I happen to have a lot of CPVC and sch80 lying around.

    Thanks again.

    plumbing4.jpg
  6. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,032
    Location:
    Cave Creek, Arizona
    If it is a rubber joint, you can reuse it after you take the PVC stub out of it. You cannot use sch. 80 fittings in a DWV system for several reasons, two of them being they are not "long turns" and the i.d. is smaller than sch. 40 pipe so they create obstacles to smooth flow. ALL fittings must be for a DWV system, NOT water piping. You cannot use CPVC because it has the wrong i.d. and o.d. to work with DWV fittings. You make the insertion using banded couplings sized for sch. 40 PVC. I do not know where you live, but unless it is in the middle of Alaska EVERY, even mediocre, supply house has ALL the fittings you need.
  7. Steve T

    Steve T New Member

    Messages:
    4
    Well neither the big box stores nor my local plumbing supplier stocked what I needed for this project, due to the foolishly ambitious height requirements for the sink drain in this location... So I special ordered a reducing street wye and a street tee, then started cutting into things and dry fitting it all together.

    Low and behold: I stood there I realized the stupid sink was too short to use comfortably! And likely has been this entire time!

    I wound up welding together some longer legs out of some stainless I had from another project, and basically went with the original "plan A" -- minus the cinder blocks. But hey, now I have the sturdiest cheapo sink on earth, plus some some hard-to-find fittings in my spare parts bin. Someday when humans are long gone, alien archeologists will find these unused fittings and my stupid sink legs and wonder what the heck was wrong with they guy that lived here.

    Lesson learned: Double check that what you're doing is what you want to do.
Similar Threads: Fitting utility
Forum Title Date
Plumbing Forum, Professional & DIY Advice What is this fitting called ? Nov 12, 2014
Plumbing Forum, Professional & DIY Advice Curved cast iron stack fitting - how to replicate with 4" ABS fittings? Nov 11, 2014
Plumbing Forum, Professional & DIY Advice Fitting 1/2-inch FNPT to Faucet Oct 19, 2014
Plumbing Forum, Professional & DIY Advice Can Hose Bib (Brass Male) Be Connected Directly to Copper (Female) Not Fitting Smoothly Oct 14, 2014
Plumbing Forum, Professional & DIY Advice PEX Cinch Fittings - Mixing Brands Sep 21, 2014

Share This Page