# Plumbing-Washing machine drain on stack **URL:** \ **Category:** Factual Questions\ **Created:** [June 8, 2013, 4:07pm UTC](https://boards.straightdope.com/t/plumbing-washing-machine-drain-on-stack/660477 "2013-06-08T16:07:17Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [June 8, 2013, 4:07pm UTC](https://boards.straightdope.com/t/plumbing-washing-machine-drain-on-stack/660477/1 "2013-06-08T16:07:17Z")
Just got a connection to the town sewers, now I have to build a stack and route the existing drains into it. That’s no problem. But we’ve never had a drain for the washing machine. Right now it drains into the sump hole and gets pumped out to a dry well. I assume I just need a joint with 1 1/2" to 2" pipe and a trap for the washing machine drain hose to go in. But any advice will be welcome. The sewer pipe comes through the wall about 18" off the floor, existing pipes are all a little over 6 feet up from the floor and run very near where the new stack will go, so that part will be easy. It’s 4" pipe coming through the wall and on the existing drain line. ---
**Author:** ![ZenBeam](https://avatars.discourse-cdn.com/v4/letter/z/3ab097/32.png) [@ZenBeam](https://boards.straightdope.com/u/ZenBeam)\ **Post date:** [June 8, 2013, 4:55pm UTC](https://boards.straightdope.com/t/plumbing-washing-machine-drain-on-stack/660477/2 "2013-06-08T16:55:51Z")
I assume the dry well is separate from the septic system? Any chance you can just leave this part alone? ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [June 8, 2013, 4:59pm UTC](https://boards.straightdope.com/t/plumbing-washing-machine-drain-on-stack/660477/3 "2013-06-08T16:59:33Z")
> [@ZenBeam](#): > > I assume the dry well is separate from the septic system? Any chance you can just leave this part alone? Yes I can. But I’d prefer not to. When there’s enough rain the well won’t stay dry, and it can’t even handle the output from the sump pump sometimes. Also, I haven’t checked, but it’s possible I’m not supposed to be draining a washing machine into it. Also, since I’m building a new stack it seems like the best time to try to do this. ---
**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\ **Post date:** [June 8, 2013, 5:55pm UTC](https://boards.straightdope.com/t/plumbing-washing-machine-drain-on-stack/660477/4 "2013-06-08T17:55:22Z")
Presumably the washing machine drain will need to be vented as well. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [June 8, 2013, 6:37pm UTC](https://boards.straightdope.com/t/plumbing-washing-machine-drain-on-stack/660477/5 "2013-06-08T18:37:40Z")
> [@friedo](#): > > Presumably the washing machine drain will need to be vented as well. The whole stack is vented, and there will be a trap for the washing machine drain. Is there something else I need? ---
**Author:** ![Michigander](https://avatars.discourse-cdn.com/v4/letter/m/ccd318/32.png) [@Michigander](https://boards.straightdope.com/u/Michigander)\ **Post date:** [June 8, 2013, 9:45pm UTC](https://boards.straightdope.com/t/plumbing-washing-machine-drain-on-stack/660477/6 "2013-06-08T21:45:59Z")
Try these pics for ideas. You need to have the standpipe opening low enough for machine to pump into it. > **[plumbing drain washing machine - Bing](http://www.bing.com/search?q=plumbing%2Bdrain%2Bwashing%2Bmachine&form=MSNH14&pc=MDMD&pq=plumbing%2Bdrain%2Bwashing&sc=1-22&sp=1&qs=AS&sk=)** > > Intelligent search from Bing makes it easier to quickly find what you’re looking for and rewards you. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [June 8, 2013, 10:34pm UTC](https://boards.straightdope.com/t/plumbing-washing-machine-drain-on-stack/660477/7 "2013-06-08T22:34:09Z")
That’s perfect. Thanks Michigander!