Nationwide roofs are sq.. A 60 cm2 bit of 4mm Correx can make a National roof by having an ‘edge’ about 6cm deep. If you prefer a further ‘edge’ you’ll have to have a larger sheet, which implies you'll be able to’t Slice two width-clever from the 1.2m broad sheet of Correx. If you employ Langstroth or some other hive form you’re your