It is pouring heat out the roof. Within the next 6 years we have plans to convert the loft to create another bedroom. Thinking long term I can't quite figure out whether I'm best to:
1 - Kingspan/Cemotex between rafters (leaving a 50mm clearance off the sarking for ventilation) but saving the drylining for another day.
2 - Kingspan/Cemotex between the joists as it'll all be floored eventually and reinsulate the water tank is it will get a lot colder in the loft above the ceiling! My thoughts were to simply cut to width, insert between joists and leave it at that after reaffixing the existing floorboards.
3 - Rockwool it all for a pittance now, only to rip it all out within a decade?
My preference is for option 1 or 2 but would welcome the thoughts of the learned souls on here as googling the subject provides a dazzling array of ways to go about it.