I am building an extension myself, the walls are going up and I need help with the roof design and timber sizes. The extension walls are constructed from Brick outerleaf, 75mm cavity and Fibolite 3.6 N internal block. I want a usable roof space and would prefer not to use trusses. Can some help me with size of ridge and hip board, Purlins and rafters,
Kindest regards.
Kindest regards.