All, I am currently looking at installing a new UFH system into my home however the current build up from the existing GF slab to the top of the door thresholds is about 30mm, although I know there are systems out there that are between 15-22mm (for example Uponor Minitec, Nuheat Lo Pro Max etc), I have been advised that in order for the UHF heating to be as efficient as possible I need to install a PIR board / insulation underneath (currently looking at recticel eurothane GP). In order to do this I will have to take up the existing screed which is also 30mm (plan to do it using an SDS drill & chisel), however this still only leaves me with a total of 60mm for the insulation, piping system and latex / screed. My questions are what build up would you propose?, could you take out say 20mm of the slab? (Guessing not as it would be structural), also what UFH system and manifold kit would you recommend? Been advised to go Uponor or Nuheat & stay away from Polypipe so far but would be interested to hear your thoughts on the above mentioned manufacturers or others. Many Thanks in advance for your comments. Jason