"Doctor Drivel" wrote:

"Matty F" wrote in message
...
On Oct 13, 7:07 am, Andy Champ wrote:

Seems to me that if you foamed the void between tank and container fully
(expanding foam foamed in place, not bits) the outer, cold, container
would take the strain, not the hot inner.

OK, so I'll look out for two containers, and use that expanding foam
stuff between them.
Perhaps I don't need a lot of insulation, and then the water won't
reach boiling point. It would be better to have a large tank at a
lower temperature.
We've never run out of hot water anyway. It costs nothing to heat it,
and the water is collected on the roof, going into a tank that holds
about 30 cubic metres.

30 cubic metres? Do you need that much hot water?


Does he need that much weight?

30 tonnes of water! I hope the foundations are built to take it.