Well, as in the previous thread of the same name I have now smashed open
the concrete surrounding the joint between the cast iron soil downpipe and
the saltglaze sewer pipe where I fancied I had a leak and found a cavity
about a cubic foot in size and a badly cracked 135 degree salt-glazed pipe
which connects into the rainwater drain from the gully, via a teeing-in
pipe.

The teeing-in pipe has cracked flanges too, though it doesn't visibly drip
water like the
cracked soil pipe connection: that lost half a cup of water each time I
flushed the loo.

Questions:_

Is it best to replace like with like, or can I use plastic sewer pipe?

Do I have to take up two sections of sewer pipe at the same time, in order
to be able to fit them together?

Is it easy to separate salt-glazed sewer pipes that have been cemented
together at the join without running the risk of fracturing the good pipe?

If there are hairline cracks on glazed pipes, can I just coat them with
something
( I dunno, like bitumen ) an bury them back in concrete?

cheers,

Andy.