So then we started laying down the insulation board, first on the greenhouse and later on the main body of the Us. The greenhouse has just 4cm of rigid insulation over the decking because we are putting rockwool in the gaps between the beams and then decking underthat (visible from the inside) while the Us have their beams on show from the inside and 12 cm of rigid insulation over the top. Then we put wooden strips to screw the corrugated metal into and filled the gaps with another 2cm of insulation. All of this got screwed into the inside beams with 26cm long screws - Oscar managed to get them all straight into the beams! We were working to a deadline here because the metal people were coming on the...can't remember which day they came but they were coming. Unfortunately in the mornings when it was cool enough to work, there was heavy dew and as everything was soaking wet we couldn't do anything. In the afternoons the wind sprang up and blew insulation all over the place so our only option was to work in the heat of the day between water and wind. It was SO hot.