Self Build - Where to put Water pipes?

[pudzer]

We poured our subfloor before Christmas. We put in waste pipes etc. however, as we didn't have a plumber on board at the time, my foreman recommended holding back on the hot and cold water pipes and suggested putting them in when power floating the floor. I thought no more about this at the time

Now, we have a plumber on board and he says that he wants the water pipes in now rather than when power floating.

When should they go in? Any suggestions would be much appreciated.

My plumber has suggested getting a kango hammer and 'cutting' troughs in the subfloor so that he can lay his pipes. I am concerned that this will compromise the subfloor.

My foreman says he's never heard the like of it and says that it's common occurence to tack the pipes to the subfloor and then cut the insulation around them. I'd rather not cut through my lovely expensive foiled-backed Kingspan - surely it would be less effective.

Oh the joys of a selfbuild and I haven't even got the floors in

 

[qwerty?]

Well we clipped our insulated pipes to the subfloor, cut a layer of 40mm Xtratherm around these, and then put a layer of 60mm xtratherm over this, so no gaps. The only chasing of the subfloor might be where you have two runs of pipe crossing each other, dish out the subfloor for this.