The roof is covered with Spanish small format slate and has an area of 360m². Main areas are at 32° with most others at 38°.
The main roof like all the exterior of the building is very thick to allow for lots of insulation.
The roof construction is as follows :-
- Slate (Spanish 300x200mm from Cupra)
- Treated softwood battens – horizontal -50x25mm
- roofing membrane
- Treated softwood battens – horizontal -38x25mm
- Plywood sheathing 12mm
- CLS Joist – 89mm
- OSB Web – glued & nailed full face along both joists with a depth of 400mm
- CLS Joist – 63mm
- Vapour control membrane
- Fermacell -12mm
Space from 5 to 9 will be filled with insulation giving a U value = 0.095