Hi, I have a large crack in a cast iron waste line. The line at that point serves just the kitchen sink and is vented to the roof. The first plumber I called wants to disconnect the P-trap, install a drum trap, drill through the cabinet and floor, and connect to the waste line down below the crack.
The reasons he wants to do this are that the crack runs quite high and is hard to get to (just below the floor rafters), and he thinks that vibration by cutting that high may cause cracks further up the line.
I'm uneasy because his recommendation essentially lowers the code-compliance (no vent, drum v. p-trap), and also introduces a whole bunch more pipes into that basement area.
Please advize!

speedball1

Some plumbers would frown on the advice I'm about to give you. First off a drum trap and the extra piping shouldn't even be considered.
The correct repair, of course, would be to tear out the old cast iron and convert to PVC. However, I like giving options, if the crack isn't too big why not fill it with JB Weld or Fast Steel, a putty that hardens into metal. You could do this yourself and save the cost of a plumbing company. Sound like a plan?? Tom

scirocco70

For creative repair options, how about one of these?

(in my experience, JB Weld would do this trick, but i'm not even a plumber's apprentice, so...)


1) Fernco or other neoprene/rubber sleeves. Would it be possible to take a no-hub rubber connector, slit the rubber, install it with the slit opposite the crack and tighten it up?

2) Sleeve the pipe internally. You can't do this yourself, but it could be done quickly. Google around and/or check YouTube for trenchless drain repair. In short, an internal sleeve of special material (kevlar/fiberglass?) is epoxied to the *inside* of the pipe by sliding it in wrapped around a long, skinny balloon. The balloon is inflated, which presses the patch against the inside of the pipe. Search on "cast iron pipe" on YouTube to see some pretty impressive videos.


None of this seems like a good idea if you don't know why the pipes cracked, and are sure that the cracks won't grow. Check the supports for the pipe, cast iron is heavy and needs a lot of support.

Adding a drum trap does seem like a bad idea.

~aaron

speedball1

In his #1 solution, ( a very good suggestion, Thanks Arron) scirocco suggested a saddle clamp,(see image) while this would work on a short crack a long one needs to be filled and patched or the pipe removed and replaced.

His #2 solution would also work although i'm not too sure of the expense.
Both of his suggestions beat out the plumber you paid to give advice.
Good luck and let us know what you decide. Tom