Part of our roof is outside the heated envelope: open to the fresh air in other words. Have a look at this image. The Durisol wraps the heated envelope: the steels the Winter Garden.
Here's a different route view of the same thing.
The area on the left is the winter garden. And while there is a window on the plan, we are now not going to have that window: just a plain roof. (Too much solar gain and too much of a Right Royal pain in the Botticelli.) The strange hatching on the roof indicates solar PV -being fitted tomorrow. Woohoo Hoo.
Now that we have decided to fit tiles the left hand area of the roof, it occurs to me that the underneath of the tiles will need to be boarded. otherwise the tiles will just be blown off their battens because the wind catches that corner of the house quite a lot.
Question. What with? OSB3? Marine ply? WBP? Plasterboard, Caba Board?
Any ideas ?