insulating the outside of a roof (warm roof).

[poshman1]

Hi everyone, hope you can help.
I've attempted to construct a warm roof, I've also used 18mm ply as sarking and then fitted 35mm counter battens, can I then use 25mm celotex between these battens and put a breather membrane on top and finally fit tile battens.
The roof will be vaulted inside, I plan to use 50mm celotex in the 100mm rafters.
Thanks.
Poshman.

 

[JohnD]

is there a question inside all that?

 

[poshman1]

Yes, sorry, is this good building practice and will it elleviate condensation