I planned to use a liquid screed but the vendor was having problems getting his mix right in the lab. I was also worried that I hadn't "tanked" the floor well enough. I'd assumed the stuff was quite thick but I was told its like milk in viscosity. My nightmare was the screed getting under the ridgid insulation and causing it to float up. I opted eventually for a sand-cement screed, drlivered in a big pile and wheeled inside in wheel barrows.
One tip I got was to fill the UFH pipes with water first to stop them floating up in the screed.
I also read that some liquid screeds can cause problems with a stone floor. I'd read that the adhesive needs to be de-coupled from the screed prior to laying. All in all I got very little useful info from any one , including the folks that sell both screed and UFH. I'd go carefully. Eveyone on Grand Designs seems to manage mind. The screed companies seemed reluctant to do a domestic job, preferring commercial work. Costs were quoted at about £1k for 70 square metres.
Good luck and please report your findings.

Hi
I am building a small bungalow using liquid screed (150mm insulation 75mm screed). I was told to tape all joints in insulation then place a thin layer of plastic over all insulation and coming up the walls 80mm, then put in underfloor heating pipes with chicken wire on top kept in placed with UFH clips to stop pipes rising.

Hope this helps.

Any more info on limecrete screed? Suppliers, price etc.