"Andrew Gabriel" wrote in message
...
In article ,
Chris J Dixon writes:
Any suggestions on the most suitable insulation to use?

Externally, you need to use a waterproof insulation so it can't
become waterlogged, also known as closed-cell. This is most commonly
used on chilled aircon pipework. Armaflex is best known make.

Internally, it doesn't much matter.

Unless it is in a vented loft.