John Jeremiah Sullivan wrote an account of getting a difficult
plumbing problem solved in 'Harpers'. Turned out his old house's cast
iron drain pipe had a longitudinal crack in the top, so only gas got
out, not water. He drove to South Carolina to buy some smoke bombs,
which he set off in front of the cleanout plug, blew the smoke in with
a fan. Even after he found the leak he had a hard time finding a
plumber to fix it. Is it possible to seal cast iron pipe the way I
hear some drain pipes are sealed with some kind of plastic coating?
It's a wacky story.
[harpers.org]

CIPP(cured in place pipe) is a liner that can be installed inside an existing compromised pipe. No sealants/coatings can be used on the outside of the pipe to "repair" it, other than a temporary fix.

[en.wikipedia.org]

steve.. please explain why a patch on the outside would be considered temporary but a patch on the inside would be better?

i have had good results by melting special hard roof tar.

i've even used small broken chips of this to throw intro the oakum before pouring a lead joint.

[www.iko.com]

First thing is a crack in a pipe is likely to keep cracking. Second is that it's specifically prohibitted by UPC in Chapter 3 - Workmanship. I don't know if IPC has similiar code section. The CIPP method has been tested/certified and is not a "patch", but a new pipe installed inside the old pipe.




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thats gonna put that guy who advertises on TV outta business