"peter" wrote in message
...
Thanks Mike

Do you think that the claim that spiral wrap from screwfix
is an equivalent to 33mm polystyrene not possible?


I think whatever dimension that 33mm is supposed to apply to it is unlikely.
If it refers to the usual wall thickness then it is extremely unbelievable.
B.Reg for climaflex insulation rating works out to be 25mm. Expanded
Polystyrene is going to be very similar if not better thermal efficiency.
Foil backing may be effective but I don't believe it beats depth of
something decent.

--
Mike W