Cast Iron Pipe Corrosion - This is Bad...

I recently finished (last weekend) remodeling my kitchen and everything went great. Today I had a problem with my dryer and pulled it away from the wall to take a look at the back. As I pulled it away I found the attached picture. I bought the house a year ago and the pipe appeared to be in fine condition with no corrosion at that time. Now it looks like it is about to explode. I'm not a plumber but know that it can't be good because the cast iron is flaking off. One piece even fell off when I touched it. This drain runs under the slab in my living room from my new kitchen to the basement laundry room. It then goes into the laundry room floor and out to the street. It is not leaking now but appears that it is in really bad shape and it is only a matter of time before it does fall apart. My question is what the heck do I do? The kitchen is the only drain that runs on this line. Everything from this point back to my kitchen sink is under the slab and runs under my new floor in the living room an under part of a giant brick fireplace. Is there any way to fix this without some serious work? Any and all help is appreciated. I have a feeling I am in trouble

-Josh

I agree, it looks bad. Cast iron replacement is not for the novice. It is connected with molten lead poured into the joint which is packed with oakum. Of course it can be replace with PVC, but that is also not something to be taken lightly...pun intend...cast iron is extremely heavy and requires special tools to cut apart. I would strong suggest you call a plumber to examine your entire drain system and see how much needs to be replaced. It may not be the entire system gone bad.

cast iron

The copper tubing has nothing to do with the corrosion. It had deteriorated from the inside, probably due to age more than anything else. Repairs will be somewhat difficult given the tight spacing of the fittings, and you probably need a plumber to do it. Converting to any other material would require more space than you have available.