Insulating 50-gallon water header tank

[Moonraker]

In my loft I have a circular 50-gallon cold water header tank which had a lash-up of insulation. (It still does.) An Internet search of suppliers in my town (population 170,000+) failed to find a suitable jacket, so I ordered one on-line (where there was hardly any choice). It proved to be very flimsy, the plastic was easy to tear and the contents settled too readily. After I'd fitted it, it looked a mess.

I've just spent an hour Googling and the best alternatives seem to be Thermowrap or old carpet!

Well-informed advice will be appreciated. If anyone endorses Thermowrap or carpet, would one layer of either be enough?

Thanks in advance.

Moonraker

 

[exedon2]

I'm lucky enough to be able to 'aquire ' biggish off cuts of superfoil insulation.
Wrapped round the tank duct tape on job done