I pulled out an old toilet and there wasn't a flange in the floor to use when installing the replacement. It looks like the bolts were drilled straight into the ground, although one of them I had to pull out to remove the toilet. I'm not sure what kind of pipe it is; it looks like concrete on the inside, but looking up at the pipe from the basement it's definitely some sort of metal; not sure if it's cast iron or if it's painted black.

Is there any way to add a flange to this without having to drill new holes through the floor?

Here are some photos of what I'm seeing. The first photo is of where the old toilet was removed. The second photo is the pipe underneath, in the basement. The pipe looks kinda grody, but it's been there for 90+ years. This is the view from where the old toilet was removed.

The pipe in the basement

  • Just below the bell on the cast is that a vent or a drain? It looks like that to me so your replacement flange can’t plug that pipe take this photo and measure the width of the bell on the flange, it may take a short section of pipe inside the bell for a drop in replacement flange to fit.
    – Ed Beal
    Commented Mar 29, 2021 at 15:47

3 Answers 3


You need to install a toilet flange for cast iron. The only thing that looks weird is that side pipe that enters and would likely be blocked by installing this flange.


You will need to install a flange to fit your existing pipe. Take some measurements and stop by your home store or a plumbing supply store. you'll probably need a close flange similar to the one below so you don't block that drain pipe

enter image description here

As with all flanges, you will still need to drill holes into the floor to secure the flange to the floor.


Do what I did.. make a base out of a 2x12 or 2x14;to lift the toilet up .. Dont run it too far forward of the base of the toilet to prevent toes from hitting it..cut out the hole for the flange. Seal the new flange to the old drain pipe.. do not not not use canned foam, it absorbs water..

  • This could use a lot of additional detail to explain what you did. As it stands, this is rather confusing. You actually lifted the toilet by 1.5"? How did you seal the flange to the existing pipe?
    – FreeMan
    Commented Jan 23, 2023 at 12:43

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