Underfloor piping

[diversion]

Hi everyone, you've been really useful to me in the past, so here goes again!
We've recently done away with a groundfloor wall between kitchen and downstairs bathroom with the intention of creating a larger kitchen. We now have various pipes in the middle of the new large room - the old bath tap pipes, the old basin pipes, the old bidet pipes and a couple of pipes belonging to the old radiator. The floor is concrete/screed and I have now to reveal and cap these pipes.
Question 1: What is the preferred method of capping - solder jointed cap, plastic cap, or compression cap?
Question 2: When these old pipes have been capped off, I'll need to dig some small trenches and pop some new radiator and sink pipes beneath the screed floor, what material should these pipes be - copper or plastic? and do they need to be protected/insulated?
Many, many thanks for any help and advice - Chris

 

[bengasman]

Solder cap is most reliable
Pipes need to be shielded from contact with concrete as it will corrode them

 

[Softus]

If the cold water pipes are carrying mains water then capping them would create dead legs, contravening the Water Regulations.

I'd be quite keen on removing ALL of the dead pipework, because I have a hunch that you'll be tiling, and fixing a leak later will cause far more upheaval than digging it out now.

Or perhaps you can find the other end of the pipework and disconnect it there.

The the new stuff, It's up to you whether you use copper or plastic, but plastic is probably quicker, and easier to avoid joints. I'd protect it with the purpose-made conduit (e.g. Hep2o HXC25 or Marley Equator).