plastic heating pipe

[stephanh]

I am prepping for extension and alterations. The existing building has copper pipe running in the screed to existing rads. and as this must be a 50 year old system, time for update before it all goes wrong!

Intending to insulate all existing exterior walls with 50mm PIR (or maybe Knauf) between studwork which will be fixed to 50x25 batten against wall (empty cavity), 18mm OSB covering studs and then 12mm placo. As this creates an area to run pipework through, I intended to drop new pipes down to rads in this fashion. Herewith my dilemma, plastic or copper?

I would like to use plastic because of it's simplicity but others have argued against it, preferring copper. I shall revert to copper through the wall to connect to rads, but still have the thing for plastic otherwise.

So, what way to go???

[JohnMo]

I would do the longer runs in Hep20 and the then convert to copper as you come out the wall. Plastic fittings tend to be big and ugly, so keep them in the wall.

[Conor]

Depends on who is doing the work and how you are pricing / managing it. If DIY, then plastic is a no-brainer. A plumber may prefer to use copper.

[G and J]

I like copper.  It feels good to use, very satisfying. 
 

But in our build we are going to use Hep2o.  
 

House I’m sitting in now I did in copper as plastic wasn’t ‘of age’ back then.  
 

18 years ago we did a full refurbishment of another property and I used Hep2o.   In hindsight the mistake I made was treating it like copper.  I don’t mean I melted the joints with a blowtorch - I mean I used elbows and connectors in the walls like I would have using 3m copper lengths.  
 

So for the build if all goes to plan there won’t be a single joint buried, just lengths of plastic pipe.  
 

And I appreciate that using copper for the final feed to each rad looks good but it does mean buried joints, and as one can buy cosmetic pipe covers why not go plastic all the way?