what is waxy paper stuff behind roof tiles?

[nigelad]

My roof has this waxy paper stuff covering the tile backs, fixed between rafters, which seems to keep the draughts out. A lot of it is torn or falling apart, and I want to get some more to replace it. What is it called and where can I get it?
Thanks for any help.

 

[Nige F]

Rice paper Building paper obsolete and crap. Get some underslating membrane

 

[nigelad]

So that's what it's called
I wonder if Jewson's do it?
Or should I just do without and let the breeze in - better than condensation problems

 

[masona]

I'm guessing you may have Vapour Barriers paper sheets ???

 

[Nige F]

I'm guessing you may have Vapour Barriers paper sheets ???

Has it got "Now wash your hands" or IZAL written on it