I would like to add a washing machine (and dryer) to my split-level home so that I can rent out the basement below (which already has its own washer/dryer). I don't have the experience to do it myself, but I'd like help deciding if my preferred location for the washer is feasible before seeking help.

My Sketch

I would like to run the drain pipe from the washer up into the ceiling of the level below, then down into the wall of the kitchen below and into the drain. Is this feasible? If so, can the p trap and venting be located as per the sketch or must they be located closer to the washer?

It would be very difficult to vent the piping near the washer as there is no existing plumbing there and there is another floor above. It is my understanding that the p trap should not be more than 5 feet from the venting, so I suspect it would not work to locate the p trap by the washer. Furthermore, doing this would increase the height the water needs to travel before dropping into the ceiling to a total of at least 60", which my research indicates is possible, but not ideal.

Can anyone confirm or deny the feasibility of the layout in my sketch and/or offer other suggestions?

UPDATE Thanks for the helpful information thus far. I understand I have two problems:

  1. The discharge water is too high above the machine.

  2. The vent stack is too far from the machine.

We haven't bought the washer yet so using a front loader on a 3' pedestal is a possibility. I guess this would solve problem #1. Problem #2 however, may make this setup unfeasible. The only solution to this might be venting out the exterior wall, which is adjacent to the washer. I understand that this isn't ideal but could it work if the vent stack exits through the wall at a 45 degree angle?

  • Would it be acceptable to raise the washer, like on a three foot tall pedestal?
    – wallyk
    Commented Aug 13, 2013 at 5:21
  • My answer to this question, and my answer to this question might be helpful. Long story short. Your plan raises the discharged water too high, and the washer may be too far from the vent.
    – Tester101
    Commented Aug 13, 2013 at 12:00
  • You could definitely vent the washer, however, you'll have to install a proper vent as per your local codes. Once you've done that, you'll have to tie the drain into the existing plumbing system.
    – Tester101
    Commented Aug 13, 2013 at 14:48

1 Answer 1


To do this right, you'll likely have to install a whole drain system for the washer. You'll install a new vent (according to local codes), and a new drain line that attaches to the existing drainage system (in a code compliant way). Then you'll install a standpipe with a trap, that the washer can discharge to.

New System

  • Thanks Tester101. If I were to raise the washer in your edited sketch up 3' on a pedestal along with a new standpipe, trap and vent, do you think the drain could then attach into the existing drainage system through the ceiling as I sketched originally?
    – Erik
    Commented Aug 13, 2013 at 15:25
  • @Erik Possibly. However, you'd have to connect to the existing drain properly (i.e. after the existing trap).
    – Tester101
    Commented Aug 13, 2013 at 15:30

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