Barrier pipe for central heating

[Davek73]

I'm looking to change my microbore pipes to plastic for central heating is it ok tpo this I'm doing 15mm copper from rad but what is best under floor thanks

 

[ReJect]

You could do the hidden pipework in 15mm for each radiator if you wished. Best it comes off 22mm pipes usually for large rads, or if doing 2 or 3 small rads from 15mm.
You need to support and clip the pipes.
Use correct insert supports to suit brand of barrier pipe.
Personally I always use copper.
Using 15mm to rads will be better than the microbore for flow rates.
You will need rads and rest of system balanced later