"Janet Baraclough.." wrote in message
...
The message
from "Sue da Nimm" . contains these words:

The pond sides should always slope outwards so that any ice formed
cannot
exert sideways pressure when it melts. (Ice EXPANDS when it melts, which
is
why it can burst pipes)


Ice expands as it freezes and shrinks as it melts. The expansion of
the frozen ice is what bursts pipes or vessels, not the melting of it.

Janet.

Sorry all - choking on humble pie - you are exactly right )
The overall effect is the same, though, ice can damage ponds if there isn't
a suitable overflow provided.

(I won't expand on the point any more in case I contract poster's cramp....)