Ive taken up the floor and found pipework below insulated with what looks like old rags (see picture).
1. Leave it as is because its fine
2. Take all the old insulation off and replace with newer/better insulation (maybe the grey foam circular stuff that has a slit in it?)
3. Leave the current insulation on and get oversized grey foam insulation to put over the whole thing (so it would be pipe wrapped in old insulation then wrapped in new insulation).
Lastly - Will the old insulation contain asbestos and therefore be dangerous to hande?