johnbarleycorn01

liquid, quick drying Gypsum based screed- not cheap £1600 approx. If you can, put as much PIR into the ground as you can afford, i could only only afford 100mm, most pewople recommend 150mm as a minimum.

You will end up with a mountain of rubble if you are knocking out the existing concrete......On a side note its worth looking into getting a concrete crusher on site, nice pile of type one ready for future projects.?

I forgot to point out the 25mm upstand of PIR and the foam expansion strip that butts up to the wall, its the little squares.

Ill try my best Gareth- what dimensions is it you want, the section of the UFH and insulation etc or the plan of the room ? If its the former its very similar to Wozzas diagram above. If its the latter i downloaded the trial version of loopcad and uploaded my cad drawings to it and spent a weekend drawing pretty shapes to design the pipe layout. I ended up with 115mm approx centres on the pipes with 4 circuits in the room. Ill get scribblin.......

Knocked out 57m2 of the old concrete, excavated the sub floor then sand, dpm, 100mm of PIR and more dpm. Then approx 400m of UFH pipe. 25mm of PIR upstand along with expansion strip foam and 75mm of free flow screed (laid by contractor)....... kept me fit over the summer doing the project and is now keeping us toasty warm over Christmas..... probably the most enjoyed end product ive ever done!! i echo the above comment in that it is easier to install than radiators etc. one thing to remember- keep the pipes under pressure when you have the screed laid. You dont need to hire or buy an expensive pressure tester, i bought one from ebay for £11 and it works fine.