The steel (iron?) fitting that passes through the basement slab and
caps off the vertical run of the 4" clay drain clean out has
deteriorated into a mass of rust. The surrounding concrete has
crumbled around the opening to about a 6-8" diameter hole. The end of
the clay riser is about 5" below the surface of the slab, and in good
shape with square edges, no cracks, etc. The vertical is clear all
the way down to the horizontal run.
I've cleaned out the debris and covered the opening temporarily. Is
there any alternative to making the existing hole wide and deep enough
to get a rubber sleeve connection on the clay pipe?
I'm pretty tempted to just drop a piece of 4" ABS into the hole (ie a
butt joint to the clay) and back fill with concrete patch.