What is the best technique for removing the entire cast iron sewer pipe in a crawl space, replacing it with PVC, and discarding the cast iron?

Do you have a problem with the cast iron?

Explain and give more detail and we can help you.

Chuck

If it is a simple removal, you would cut the cast iron out with a sawzall or a chain cutter, get some DWV PVC and use shielded couplings to join them together. Why replace everything? Leaks?

I agree. A chain cutter is quick, but if the old cast is weak you may crush it more than cut it with the chain cutter. A sawzall with a good metal cutting blade also works okay. Another option is an angle grinder with a metal or diamond bit wheel (gloves and safety goggles or even a full face shield are a must here, okay?) I just did a cut on six inch hard hard cast and a four inch cut with angle grinder with a thin metal disc. I cut from about 8 oclock to 4 oclock with the grinder then finished the bottom cuts with a cheap metal sawzall blade. One reason I did the bottom cuts with the sawzall was because the bottom portion was loaded with goodness and the grinder was flinging that stuff everywhere. Also, I didn't want my grinder blade to get bound up and shatter into flying shrapnel where as a sawzall would merely get "stuck".

Lee.

I'll tell you guys what's the easiest and fastest way to cut old soil pipe out. It's not a change cutter, it's not a Saws-All, it's a three pound hammer,
Put on a set of goggles and break that sucker out and do the job in PVC. Cast iron is brittle and break easily. You can turn the old cast iron into the junkyard for a few bucks, Good luck, Tom

I agree with mygirlsdad, crawl space soil pipe demolition can be messy business, & since a plumbers main responsibilities are to protect health, & provide sanitation, we always take extra care not to have sharp shards of bacteria laden iron ricocheting around the basement.
We use a sawsall with a diamond blade, to cut the iron into manageble lengths, & then tape the ends of the pipe as we go. We wear coveralls, safety glasses, gloves, etc, and cover the fallout area with plastic drop clothes. We also have a pail of water nearby, with a couple of drops of bleach in it, to rinse tools, blades, body parts etc..

I guess I'm just a old-school plumber. We didn't put our space suits for went into a crawlspace. We just went in and did the job and tha fastest way. Repair plumbers are used to messy jobs. While Mike may be saving the nation's health it sounds to me like he's simply upihng the labor cost. But from a health angle mode I do agree with him.
Regards, Tom

Yep Tom, I normally just dig in too, mess of no mess, but if I look at a job that I will be doing later, and see, for example, that the sewer has been leaking and the crawl is full of human waste etc, I will plan my attach a little more carefully, bisqueen, muckboots , etc. And you are correct, a two pound hammer does work wonder on cast, especially if you are lucky enough to have room to break a hub. But if the hub is the wrong end of the pipe that needs to be replaced, you need a way to cut the cast straight, and a two pounder won't do that. Normally you can get away with breaking one hub and making one cut. I will always choose breaking a hub before making a cut if the circumstances allow. And don't kid yourself, Tom, there is still some really tough cast out there. Yes much of it is brittle, but not all. I seem to find all the "like new high grade" cast. Just my luck I guess.