Corroded cast iron drain pipe

[Gastronomique]

Greetings. I have a cast iron drain pipe in the corner of my basement that appears to the corroded and getting worse over time. The lower three feet or so of the drain pipe is cast iron. The upper part is PVC. There has been no leakage or unintentional discharge up to now to my knowledge.

My questions are:

As a short-term remedy, would it help to tightly wrap some metal tape or other material around the corroding area? What if I also attached clamped rubber material over the tape to create a tight seal?

If full replacement of the drain pipe is necessary, must it be replaced all the way under the foundation? Will l need to jackhammer it out?

What type of piping should I use to replace it?

Is there a way I can do this over a period of time? Or do I need to do it in one day to avoid problems with drainage matter?

Any suggestions are welcome. Thanks.

 

[breplum]

Wrapping will not help. It can go any number of months or years w/o actually starting to leak, or not.
Code for allowed materials depends on how many stories and your jurisdiction’s rules. Cast iron is much more quiet.
PVC or ABS can be fine if noise is not an issue, pipe support is adequate and you are under three stories.
Cutting down near the floor, adding a clean out, and also scoping with video camera would be the best approach.
You need a good plumber.

 

[Geofd]

Yep breplumb is right you gotta get a camera down there hopefully it's just to the next fitting

 

[MicEd69]

Has that line always been open like that, or have you stored any materials next to that pipe? If so, that could be external corrosion.

My mother had a cabinet that opened up to the piping to her copper pipes to her tub. She had a can of Drano in it, but never really opened it up for literally years. It apparently was touching the cold-water line which apparently sweated and finally soaked the cardboard Drano container. The constant contact with Drano caused a pinhole leak in the copper line.

However, that cast iron is pretty well "honeycombed", and if it is caused from internal corrosion that is breaking through to the outside, it needs to be replaced. And blowing up your picture, it appears that there are some pretty deep pits right at the bottom next to the concrete floor.

Now what I'm about to say should not be taken as a suggestion, but just something that I've done with good success on corroded cast iron that I knew was from external sources. I've mechanically cleaned pitted cast iron pipes with wire brushes. Then mixed up some Bondo automotive body filler and worked it into the pitted cast iron.

The issue you may have, as pictures are a poor substitute to actually seeing the problem firsthand, is that if you start to clean that honeycombed area as well as it needs to be to coat it with Bondo, you may actually poke a hole in the cast iron pipe even if the corrosion is from an external source. And it the problem is from an internal source that cast iron pipe is VERY weak in that area. And as breplum indicated, any temporary fix will last as long as it will last; a week, a month, a year.......

 

[Gastronomique]

Thanks to all who replied to my posting. I appreciate the help. I'm calling plumbers to get estimates to replace the pipe and run a camera below the foundation.