A few pics of our UFH install completed last year.
Ground floor was suspended floor in part of the house and solid in the hall and kitchen.
Now it's 125mm (5") foil backed PIR with PEX at 100mm (4") centres and 125mm (5") screed.

http://ecorenovator.org/forum/attach...1&d=1388869231

http://ecorenovator.org/forum/attach...1&d=1388869231

http://ecorenovator.org/forum/attach...1&d=1388869425

http://ecorenovator.org/forum/attach...1&d=1388869498

http://ecorenovator.org/forum/attach...1&d=1388869231

http://ecorenovator.org/forum/attach...1&d=1388869231

http://ecorenovator.org/forum/attach...1&d=1388869231

First floor is PEX with aluminium spreader plates and 40mm foil backed PIR underneath.

http://ecorenovator.org/forum/attach...1&d=1388869231

http://ecorenovator.org/forum/attach...1&d=1388869231

4 zones on each floor although currently uncontrolled.