Since we already had the scaffolding set up on the top floor, material ready and a “full steam ahead” mantra still lingering, we decided to go ahead and finish the roof insulation. Hence we added a 70 mm layer insulation layer and added a 145 mm layer beneath… and ample breathing space between isolation and roof structure.
One last thing to figure out is how to secure the roof to the brick structure. As of now, there are 4 thick steel wires in place to hold the roof structure down if heavy winds would be tempted to carry it far, far away. The wire setup is made to withstand up to 4 metric tonnes of force, so I’m not worried… but a more aesthetic path will eventually be ventured.