1

I have a new bathroom which plumbs the shower into the main stack via a 2” PVC pipe. My understanding is that the distance from the trap weir to a (in this case wet) vent can be up to 8”.

My shower weir-to-vent distance is about 7'9", properly graded at 1/4” per foot, so it would appear I am in the clear as far as siphoning and any vent issues go. However, I am hearing different takes on whether my long drain constitutes a trap arm which should not be more than 5’ in length.

enter image description here

Just in case, I installed a separate extra vent (pointed to in red) to the right of the p-trap, that goes through the wall in the shower and into the attic, where it terminates in a AAV (Studor valve), which in itself is legal per my local regulations (and IPC 2015).

extra vent1

extra vent2

extra vent3

My questions:

  1. Is my sub-8-foot weir-to-vent plumbing to code as far as IPC 2015?
  2. If it is not, will my extra vent be an IPC 2015-permissible way to vent the shower?
  3. I don’t like the idea of having metal straps rubbing against the PVC piping, so I am inserting rubber between them (see example photo). Is there anything wrong with that? rubber gasket
Improve this question
1
  • Anyone? Bueller?
    – sil80
    Commented Jun 22, 2021 at 13:43

1 Answer 1

Reset to default
1

Your vent configuration is fine, if unusual.

Not sure about the rubber bushing. Seems like you are inventing a solution to metal straps severing PVC pipes. I've never noticed an epidemic of metal straps severing PVC. If you don't want to use the strap, replace it with a J-hook. They are sold at any plumbing supplier.

Improve this answer
3
  • Jeff, much appreciate the response. For my own understanding, is there something I am missing in the whole 5ft vs 8ft trap arm length for 2" waste lines? In what case is one vs the other applicable?
    – sil80
    Commented Jun 22, 2021 at 15:54
  • UPC has a table specifying a max trap arm of 5-feet for a 2" drain. My read of your post is that you are under IPC.
    – Jeff Wheeler
    Commented Jun 22, 2021 at 19:15
  • 1
    Looks like there are differentiations between the code - UPC states 5' max trap to vent, while IPC 2015 states 8' max trap to vent. I am in an IPC 2015 land, so my 7'9" trap arm length should be ok. I thought I was going crazy and misunderstanding definitions within the same code, but the codes are just different.
    – sil80
    Commented Jun 22, 2021 at 19:32

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.