I would like to add a wash machine to the basement. Near the area of the basement where I'll be adding it is a 4 in drain coming from an upstairs toilet. Can I tap the new drain into the toilet drain?

  • Can you post a picture? It sounds like what you are describing as the "4 in drain from a toilet" is your stack. If so this is fine. – jamietre Nov 30 '12 at 10:30
  • 3
    will need a trap for the washer drain. Don't forget! – shirlock homes Nov 30 '12 at 10:39
  • 2
    The trap arm must be properly vented. Don't forget! – bcworkz Nov 30 '12 at 21:53

You can tap in to the existing stack to drain, the only issue (like bcworkz said above) is you need proper venting. If you were to tap in to that stack without a vent, you could potential pull the water out of any traps above (via suction).

|improve this answer|||||
  • I would also recommend there be a horizontal run of pipe from the stack at least 18" long before the washer trap, even if properly vented. – mfarver Aug 26 '13 at 23:26

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.