Outside pipe insulation

[Gav74]

Hi all.

I have a 3 foot run of plastic 22mm pipe which runs outside the house. I need to protect it from the frost, but the conventional DIY store insulation looks like it'll soak up the rain and freeze itself.
Is it OK to use the standard stuff or is there something more suitable?

 

[PrenticeBoyofDerry]

Why does it need protecting from the frost, if it's a waste pipe and run in downward angle, should not really ever contain enough water to freeze.
But why is it 22mm?
Should really be 40mm

 

[seco services]

more like condensate pipe.

 

[kevplumb]

armaflex

 

[OLLIE20]

After last winter i learnt the most expensive to the cheapest, none of it works at -13, this country just doesnt work at them temps