Cast iron longevity

My house is 53 years old, build on a raised foundation. I am about to do a major bathroom remodel and am wondering what my chances are of having to replace the cast iron waste pipe that runs 5 ft from the main vent stack out thru the foundation wall. This pipe is buried in a couple inches of dirt (clay soil, neutral acidity.) Floor boards can be taken out during this remodel so it would be easier to dig out this pipe than trying to do it while laying in the crawl space.
If there is not a noticable amount of corrosion on the outside of this pipe can I count on it lasting another 53 years? Or should I plan my remodel budget to give some $$ to replacing this pipe on general principles? Can I connect new ABS to the cast iron just before it exits thru the foundation? Should I also plan to replace all the cast iron C.F.s, arms to the stack, the sani-T's, and any other stuff with ABS?

There is absolutely no "hard and fast rule" to give you an answer. The only way to tell is to open the pipe and look inside it. The outside appearance has little to do with the pipe's integrity.

Now is the time to replace,while you can.

No way to know for sure. As a ball park number...53 years is a good life for cast iron, and many houses have issues long before that. I suspect that "the book" would give 50 years as the expected longevity of cast iron in a house, and the chances of getting another 50 are not so good.

In the city of San Diego, many of the older water mains are cast iron, and at 100 years are bursting faster than they can replace them.

quote; In the city of San Diego, many of the older water mains are cast iron, and at 100 years are bursting faster than they can replace them.

And I will bet there are many buildings OLDER than 100 years with cast iron drain systems which are still working perfectly.

hj said:

quote; In the city of San Diego, many of the older water mains are cast iron, and at 100 years are bursting faster than they can replace them.

And I will bet there are many buildings OLDER than 100 years with cast iron drain systems which are still working perfectly.

Click to expand...

Under the rules of the historic commission, any building over 49 years old is potentially historic, and you may be restricted in remodeling. There probably aren't more than 3 buildings in the whole city over 100. Packy should get a laugh about all this.