Hi, a real newbie here. We’ve just bought a house with a very decent 5x4.5m conservatory, double hipped, coming off two house walls. The problem is the polycarbonate roof, which we plan to have internally insulated with a multi foil (with air gap) and UPVC cladding. I wondered, as an extra waterproof and insulation method, whether we could also put some box profile roofing sheets over the top of the existing poly roof, with additional air gap and multi foil layer between. I know the best solution would be to replace the roof with a solid one, but hoped this might be an alternative.
Would it work?