ABS Toilet Flange Into Cast Iron Pipe

[Anthony S.]

Hello,

I am in the middle of a toilet replacement in my bathroom and when I removed my old toilet, I discovered that the toilet flange was installed as follows:

There is a 3" cast iron waste pipe (vertical), ending about 8 inches below the floor level. Into that cast iron pipe, a 3" ABS pipe with a toilet flange was inserted. The ABS assembly is one foot long so roughly about 4" of the ABS pipe are inside the cast iron. The ABS assembly is not secured in any way to the cast iron pipe. I am wondering, what would a better way to do this? Would something like the Fernco 3" by 3" donut work in this case in order to join the ABS pipe to the cast iron? Something like this?
https://www.homedepot.com/p/3-in-Se...h-40-PVC-Compression-Donut-P33U-305/100170789

Thanks!

 

[Terry]

Do you mean a 4" cast iron pipe with a 3" ABS pipe inside it without any coupling there?
They do make shielded couplings for that purpose.

 

[Sponsor]

 

[Anthony S.]

No, both pipes seem to be of nearly the same diameter of 3". The cast iron pipe seems to be a tiny bit larger so the ABS pipe fits into it but it's a very tight fit (I couldn't push it any further than the 4 inch depth). It's also a bit weird but it looks like the ending of the cast iron pipe has been flared (probably to insert the ABS pipe easier). I will post a picture when I get home.

 

[MKS]

A tape measure and pictures would help.

 

[FullySprinklered]

You may be looking at lead pipe down there. Hard to flare cast iron without a blast furnace. Otherwise, it could be the bell end of a cast iron pipe or fitting.

 

[Anthony S.]

Hi all, I went back to take a more careful look and measure it. It is indeed 4" in diameter and now that I've taken a better look at it, it doesn't look like cast iron to me at all. I've tried the edges and they are bendable by hand. My house was built in 1965 so could this be a clay pipe or maybe a "coal tar-impregnated wood fibre" (aka the “Orangeburg" pipe)? I found an article which said apparently it was a thing in Canada after WWII...

I've uploaded some images: First image is the ABS assembly and the second image is the picture of the pipe

 

[Terry]

What you have is a cast iron pipe with a hub and buried in that is a lead pipe.
Once you remove the brass bushing and the lead in the joint, you can then use the rubber insert for the plastic pipe that will fit in there.

You normally find them like this.

 

[Anthony S.]

Thanks Terry, so basically I need to figure out where the lead pipe connects to the iron cast pipe (which I can see nearby going into a wall in that direction, so it must be somewhere nearby in the wall) and replace the section up to the iron cast pipe, right?