What you see in the picture is the main stack (background, green) and two other pipes joining it . You can also see two perforated straps that were used to support the pipe just below the join with the pipe that goes to the left (that goes to the upstairs toilet, blue on the picture)

I am closing the ceiling back and I think that I removed some sort of pipe (red in the picture) that was there connecting the two perforated straps, they both have loops and screws to tighten those loops

I want to put that piece of pipe back or if you have a better solution please suggest it. Can that pipe be any material or it must be a certain type (I think it was copper) I know that as with aluminum if you leave copper in contact with certain metals you could have issues

Update: how about riser clamps ? Maybe I should add one when I open the wall in the upstairs bathroom. The reason why I am worried about this is because it seems that a long time ago someone cut the copper 4" stack at the entry point in the basement slab and replaced that with ABS so now the entire stack sits on a rubber connector that makes the transition from copper to ABS ...it seems OK but I think it is a little bit compressed and if it is not lifted a bit it will end up cracking some time in the future. It might never happen and there might be some support, that I am not able to see now, with a raiser clamp in the ground level bathroom wall that is above. enter image description here

enter image description here

  • 1
    Just an electrician point of view , it may be possible but growing up doing copper pipe I never got a recall on copper coated straps but I was doing replacement work with copper pipe and chicken wire holding it and insulation/ and zinc straps on copper both leaked because electrolysis. But not a plumber
    – Ed Beal
    Aug 24, 2021 at 1:43

1 Answer 1


It is best practice to isolate copper from dissimilar metals to prevent galvanic corrosion. This includes hangers and supports.

In my area, when copper pipes come in contact with a dissimilar metal we wrap the copper pipe with Polyken 930-35 tape. This is a product designed to provide long term corrosion prevention. It's a black rubbery like tape, somewhat like a thicker and wider electrical tape.

For something like in your picture, you could simply wrap the pipe with electrical tape.

  • what about the riser clamp that I posted in the update of my question?
    – MiniMe
    Aug 24, 2021 at 1:16
  • 1
    Adding a riser clamp is fine. I would still wrap either the pipe or the riser clamp.
    – pdd
    Aug 24, 2021 at 23:52

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.