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 :-

  1. Slate (Spanish 300x200mm from Cupra)
  2. Treated softwood battens – horizontal -50x25mm
  3. roofing membrane
  4. Treated softwood battens – horizontal -38x25mm
  5. Plywood sheathing 12mm
  6. CLS Joist – 89mm
  7. OSB Web – glued & nailed full face along both joists with a depth of 400mm
  8. CLS Joist – 63mm
  9. Vapour control membrane
  10. Battens
  11. Fermacell -12mm

Space from 5 to 9 will be filled with insulation giving a U value = 0.095