A number of years ago I had a plumber out who told me what type of waste stack this is, but I've since forgotten, and cannot find info online. He indicated that it should be replaced eventually (of course, that is any pipe, but you know what I mean). For reference, the home was built in 1952.

enter image description here enter image description here

We are now working on our upstairs bathroom and have an opportunity to replace this stack because of open walls. What kind of stack is this, and would we run into any issues attempting to remove it or join new PVC into it? Is there an asbestos risk? The join and the texture may help with identifying the pipe...

There is also what I assume to be cast iron waste pipes joined into this stack. In the below image, the cast iron pipe goes from the toilet drain, to the sink, into the wall on the right where it meets with the mystery stack pipe. enter image description here

We are rearranging the upstairs bathroom so will likely remove the old cast iron pipes (which you can see have leaked before) and replace with PVC, joined into either the existing mystery stack or a new PVC stack.

Edit: Added photo of pipe defect/damage: enter image description here

  • Could be bituminous.
    – isherwood
    Commented May 18, 2020 at 18:52
  • It doesn't matter. I have removed the exact same pipe type from older homes - it is not cast iron for sure and might be some type of clay material (or clay like). I didn't do a DNA test on it. I know that the outside peals when you crack it. You have to get rid of it if you are replacing your plumbing, don't worry about the minutia.
    – DMoore
    Commented May 18, 2020 at 18:58
  • I could not remember what it was made of I thought it was tar as we used asphalt to seal it , but I have replaced much more than the few homes I helped to install it in. on line said pitch and wood. The place you may have asbestos is the oakum packing on the cast I know some was made with asbestos this is the packing that is hammered into the cast prior to pouring the lead seal. Proper spelling orangeburg .
    – Ed Beal
    Commented May 18, 2020 at 19:07
  • @EdBeal, thank you for the extra information about the cast pipes! I had no idea about oakum packing. I'll likely try to remove the whole thing at once, or cut in between the joints so I don't have to worry about the asbestos.
    – Scheer
    Commented May 18, 2020 at 19:13
  • There is not much and not all oakum had asbestos but I have run into it enough times so I warn others. Better that we are safe. If white strings it may be asbestos brown is rope.
    – Ed Beal
    Commented May 18, 2020 at 19:19

1 Answer 1


The black is Orangeburg pipe, a layered (tar-based?) pipe. I did not think it was allowed inside, I have only ever found it as vents not as drains inside , yes it should be replaced with plastic , it usually falls apart in ground but your’s looks to be in good shape, (that could be ready to fail) , yes replace it if doing any remodeling before it breaks. Tapping with a mallet can break it you will see when you start taking it apart. I have seen remnants inside but not in use I should say.

  • Thanks, that description is definitely ringing a bell! It seems in pretty good condition still (doesn't feel soft, no give). But in a few of the photos you can see minor defects in the pipe. Added a new photo with a closeup of the damage.
    – Scheer
    Commented May 18, 2020 at 19:03
  • If I cannot remove the stack all the way up to the roof, is there an acceptable way of joining PVC in? I should be able to remove it all the way to bottom, but not sure about up through the attic and the roof.
    – Scheer
    Commented May 18, 2020 at 19:07
  • Yes it is called a no-hub or fernco it is a rubber hub that joins the 2 materials together, a dry vent would be the only place I would leave this in my home if the piece above the roof was in good shape. Thanks @isherwood I went back to edit but you were so I just left a comment.
    – Ed Beal
    Commented May 18, 2020 at 19:12

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