Hi all,
I am designing a pergola roof and need some advice re insulation / condensation control.
The roof will be pitched (21 degree) to a ridge beam with rafters at about 900mm spacing. Then will be batterns and a colorbond roof. On the under side I am proposing a zincalum 'ceiling' (lining) sheet (either custom orb or mini orb profile), screwed to the underside of the batterns i.e. leaving the rafters exposed from underneath. I would like to insulate between the two metal sheets. Would I be better off using an anticon blanket under the roof sheeting, with an air gap the thickness of the battern, or just filling the battern spacings with bulk insulation (batts)? Do I need to be worried about condensation control between these two metal sheets?
I need the insulation to perform in both directions i.e. reduce summer heat from above as well as trap winter warmth from below.
Interested to know everyone's thoughts.