BS lagging for outdoor pipes is as thick as your arm. Climaflex is a good brand but for outdoor use I think you need Armaflex.
I would be thinking about a plastic trunking to box it in, I only know the stuff sold for Electrical work, which has a removable cap and is rigid UPVC. You can paint it with non-drip gloss to blend or tone with the colour of your wall.
I would be thinking about a plastic trunking to box it in, I only know the stuff sold for Electrical work, which has a removable cap and is rigid UPVC. You can paint it with non-drip gloss to blend or tone with the colour of your wall.