My house was built on a slab in1964 and has a walk out basement. There is a floor drain in my basement, along with a toilet & utility sink. Water from the main floor fixtures is backing up through the basement floor drain. I am unable to find a cleanout inside or outside. However, there is a large stack with a plug about 3' from the floor in the basement. Is this the main line cleanout? Thanks for any assistance! (https://i.sstatic.net/VTC1N.jpg)

  • 1
    A photo of the stack would be helpful is this stack a pipe possibly a back flow preventer.
    – Ed Beal
    Jun 12, 2018 at 19:09
  • I've added a photo.
    – PeoriaRose
    Jun 13, 2018 at 3:07
  • I would think that could be a clean out. I have not seen copper used with cast but a snake would be easy to run down the access.
    – Ed Beal
    Jun 13, 2018 at 14:49

1 Answer 1


Yes, it’s probably a “wall cleanout”. We like them installed on a wall above (at a higher elevation) than a tub drain, or toilet, etc. so that the cap can be removed and the drain cleaned out (snake extended down the drain) without sewage gushing out the cleanout.

  • I agree but be cautious if the plug is bad you may have several feet of pipe full of waste water when you open it.
    – Ed Beal
    Jun 13, 2018 at 14:51
  • @EdBeal Hmmm...Copper to cast iron...very strange...I don’t understand that.
    – Lee Sam
    Jun 13, 2018 at 14:56
  • That's why I mentioned it also a brass plug those are very expensive items shown in the photo but I have only seen cast used in waste lines for residential.
    – Ed Beal
    Jun 13, 2018 at 15:11
  • Thanks for all the input! I'll let you know what happens if I can get the plug out.
    – PeoriaRose
    Jun 13, 2018 at 17:54

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