In article
,
RobertL writes
On Dec 21, 6:07*am, Mike Tomlinson wrote:
In article
s.com, Jim writes

That is to say, fix all the floorboards, then lay celotex/kingspan
(I'll have to look those up), then foil tape on top of that, and then
let the fitters lay underlay and carpet ontop of that?

Celotex is a foil-backed insulation mat, about an inch thick. *

For the OP's situtaion it will need to be about 100mm thick to meet
building regs. The required thickness depends on the (exposed
perimiter)/area of the floor. take a look he
http://www.insulation.kingspan.com/uk/pdf/tf73.pdf to see how thick it
needs to be.

That's pointing to Kingspan Thermafloor which is polystyrene, PIR foam
thickness should be about half of that for the same thermal properties
so say 50mm.
--
fred
FIVE TV's superbright logo - not the DOG's, it's ********