This is the rough in in question. On the washer service, for the Oatey Sure Vent, is the DMV Tee installed facing the right direction?enter image description here

  • 3
    That's just a vent. What about the two straight tees at the end of both trap arms? What about all the chopped out studs on the right creating a cantilevered header?
    – jay613
    Commented Nov 1, 2023 at 9:00
  • 2
    @jay613 While it's not a sure thing just from the photo, this definitely looks like a non-load bearing wall being built flush against the existing load bearing exterior wall. Those studs are more like furring strips than support. Even so, there should be drill plates in front of all that pipe...
    – Logarr
    Commented Nov 1, 2023 at 16:26
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    @Logarr agreed re the new wall, I'm looking at the original wall. There's a disused window opening. The king stud is dangling mid-air, there's no jack and the header is supported by a pair of studs sitting on the window sill that itself appears to be unsupported on the right. Maybe it's supported a little by the Jenga assembly around the vent coming from downstairs? IDK, to me the whole thing appears cantilevered over the cripple studs via a couple of new studs inside the window opening. Maybe there's something hidden by the insulation.
    – jay613
    Commented Nov 1, 2023 at 17:53
  • @jay613 Oooooh now I see what you're seeing. Yeah that whole joist immediately left of the drain stack is being supported very indirectly at best.
    – Logarr
    Commented Nov 1, 2023 at 18:14

2 Answers 2


Yes, it's backwards. That's an air admittance valve at the top, though. That's a vent. Any ol' tee pointing up is fine. Unprofessional but fine. I suppose an inspector could point to IPC 905.2 to say that the sanitary tee isn't connected to drain back to the drainage pipe. It's a silly claim to make, but your installation does look funny. Sometimes that's enough to snowball into a rejection.

I'd fix it. Funny thing is, a santee still looks funny even oriented correctly because it's no good for drainage, never mind that yours is for venting. An inspector might want to see a wye+45.

If I was an honest inspector and desperate to save face, I would say that a snake can go up the current backwards santee. You would then fail under the UPC's workmanship prescriptions. I don't know the IPC well enough to find an analogous face-saving loophole.


Yes it is. The usage of a sanitary tee at all in that horizontal configuration is also a technical violation of many plumbing codes, but allowable in some places in some conditions. That said, it is very unlikely to pose an actual functional problem.

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