Replacing copper plumbing

[yottie]

I suffered last winter with pipe splits in an outside laundry room. I now have the plastic replacement bits ready to go. Would very much appreciate advice on the following please before I start : I have some braided flexible piping in the system at present, do I need to replace these. The blue mains pipe comes up into the room and I am going as near to it as possible, do I need to replace present brass in-line isolators in the system or will they be OK (for frost damage) if just attached to the plastic piping. There is an outside tap which is connected to the piping with a tee junction , the copper feed (5") then goes through a hole in the wall, can I leave this connection alone and just connect the new piping above and below the present tee junction.
Any other advice would be appreciated. Have just found an earth strap going from the SS sink to the present copper piping, do I need this now.
Many thanks

 

[electronicsuk]

Plastic pipe can split or push off the fittings when it freezes, so using it to replace copper seems like a waste of time and money. You would be better installing trace heating and pipe lagging, or providing some level of background heating in the room during winter.