This discussion has been about lead wiring.

Another type of cable sometimes used c. 50 years ago for ring mains
consisted of a copper sheath, a ceramic insulator and then the live and
neutral leads inside that, cased I thinkk in rubber. The whole about
1/3 inch in diameter.
while lead cable was used for lighting in our house, this copper/ceramic
cable was used for the ringmain power crcuits in our old house. I think
it was installed in the late 50s for my parents.

What we saw by 2000 was increasing incidents of short circuits (via the
copper exterior) and blown fuses. Eventually whole circuits became
unusable. Regular slight movements, duw to floor boards & joists
flexing as people moved about, had caused the ceramic to crumble. then
maybe some damp penetrated and shorts were the result.

This was eventually one of the final things that led us to persuade
widowed mother in her late 80s that the house was no longer safe for
her, poor lady.
The week after a major furniture moving exercise which obiously
disturbed floor boards even more, the entire kitchen circuit packed up.

So in 2000 we took over and had to replace the lot immediately.

Of course if you have to live with it for a short while, the advice
about not disturbing it applies to this just as for the lead cables.

So, Matt, do you have any cable like that in your ring mains?

David H-S