Insulating boiler heating

[kbearn]

Hi everyone.
i am working on a project at present to re-insulate the heating pipes from the boilerhouse to the house. The pipes have about 12 metres to run and I havebeen digging by hand. I had proposed to insulate them with standard pipe insulation. however I have seen examples on uTube where the pipes were then encased in fiberglass insulation and then water pipe for protection.
Others have used expanding foam to encase the pipe. has anyone any experience of this?

Paul

 

[HITGAS]

Standard practice on commercial systems are to use silver backed fibre glass insulation. I think this is very expensive I remember quoting £50 a metre.