Facing a difficult decision regarding furring of the slanted roof in a Småland villa. The rafters are set at cc600 and cc1200 which need to be spliced, covered with a waterproof layer, followed by furring and plastering. Ideally, I would furr with 45x45 at cc450 as it provides a good installation layer with proper distance to the waterproofing, and allows for the use of 410mm insulation panels and 900mm gypsum. However, will the gypsum sag if 45x45 cc450 is placed over rafters at cc1200? How bad would that be? Is it a disaster or just a bit thrifty?
I read somewhere that you can avoid this if you screw the gypsum vertically instead of along the furring. Thoughts on that?
