2

I needed to replace my dishwasher, and found out that the new one is a bit bigger and does not fit under my counter... There is a 1 1/2" horizontal pipe that passes in front of the wall, under the countertop. The dishwasher touches the pipe and need to go in another 2 inches to be flush to the countertop. I cannot slide in the dishwasher far enough under the countertop because of that pipe... See first image (the red square is the dishwasher placement).

Does this change of layout require additional venting, like the green line that I added to the second image?

Original layout

My solution was to redirect the pipe so it passes closer to the ground (see second image). The pipe was lowered about 12 inches.

Modification done

Improve this question
1
  • Questions to help avoid an AAV if you want to avoid it: 1) Which way do the joists go under the floor of this room? 2) Is the ceiling vaulted as drawn or is there a flat ceiling and an attic? 3) Is the wall behind the sink a hollow stud wall?
    – jay613
    Commented Sep 7, 2023 at 0:36

1 Answer 1

Reset to default
4

Yes, it does, because the new layout results in an S-trap. You can't drop vertically prior to joining the vented stack. The plan you've drawn with an upper vent branch is a good solution. Be sure to use a sanitary tee and not other types of tees.

Improve this answer
5
  • @jay613, did you mean to put this on the question? It doesn't seem relevant to this answer.
    – isherwood
    Commented Sep 6, 2023 at 13:03
  • An AAV would also work, no?
    – Huesmann
    Commented Sep 6, 2023 at 14:01
  • AAVs aren't allowed in many jurisdictions.
    – isherwood
    Commented Sep 6, 2023 at 14:13
  • After verifying, AAV are allowed in my area if used where it is impossible to connect a vent without opening a floor or a wall. Which is my case, since there is not enough room below the countertop to pass the 1 1/2 inch venting without opening the wall...
    – Philippe
    Commented Sep 6, 2023 at 19:04
  • Note that the new vent should not go horizontal until it is above the sink's flood-level rim.
    – pdd
    Commented Oct 11, 2023 at 18:32

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

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