Also... :)
re: new extension
I'm looking at doing the 2 new rooms as an extension of our UFH but am wondering the best system to put down as it would be on top of the 4" slab (which is laid on top of the 4" Cellotex) and within the 70mm screed. Main concerns are fixing to slab and excessive heat-up and cool-down times if the pipes/screed isn't isolated from the slab.
The new "cinema room" is quite small at 3m x 4m so could get away with a small radiator but the other half of the extension is a "landing" with floor to ceiling windows so nowhere to fit a radiator and would prefer to run as a single UFH circuit from the radiator circuit that currently only feeds a single towel rail in the shower room.
No internet at home makes it difficult to do out-of-hours research and at work I'm distracted by work. :)
Cheers Pete