Filling around copper pipes

[wowfudge]

We've had some radiators moved and I need to fill around the pipework where it's chased into plasterboard and plaster and the gaps won't be hidden by the skirtings.

What's the best way to do this? I know concrete corrodes copper, but what about other fillers? Stupidly DP told the plumber we'd do it when he was going to as part of the job. Of course DP is crap at that kind of thing so it will fall to me. I'm thinking of using something like this with a fine filler or skim type product over the top so the different texture doesn't show through once painted. Do I need to pack round the pipes first or protect them in any way?

An alternative might be to put some foam pipe insulation on, then use expanding foam and filler over the top. That way there should be no issues with expansion and contraction noise, nothing chemical in direct contact with the copper and less filling to do.

Obviously I could use foam pipe insulation when using filler of some sort rather than expanding foam.

Hmm, to be honest I'm only a novice but I wouldn't want to fill in around heating pipes. How would you access them if there were a leak? Think of the damage! We have wires and cables chased into the plaster but any supply pipes we've always had boxed. Is there any way to have them in some sort of ducting, or board over where they're set into the wall and then fill the surface so it's flush? And I guess you'd have to insulate them first too.

They're on the ground floor with a solid floor under them. Any leaks would soon show and we're only talking about relatively small areas above the skirting needing to be filled.

What I am thinking of doing is very much like boarding them over and filling really - I don't want to use lots of plaster type filler.

I'd just worry about them expanding and contracting with the temperature of the water in them, but I guess if it's only a small area the chance of the filler showing cracks wouldn't be too off-putting :) if possible I guess finding a way of making them flush but still leaving done space around them would be ideal, rather than completely filling the cavity.

Pics would help, but unless they're chased very deep you won't get enough cover with solid plaster to avoid cracking from expansion and movement.
In our case I chased relatively deep (the walls are 9 inch solid) and set the 10mm pipes in expanding foam with some 20mm oval electrical conduit around. Then I used some one coat plaster over the top. This gives room to expand but still good cover.
In your case you might need some kind of board over to allow movement.