hi everyone just about starting my ceiling project using furring strips.The strips i am using will be 1x3 strips,would i be better using 1 layer of 9.5mm plasterboard with one tube of greenglue and 2layers of 12.5mm with green glue inbetween, or just use 2 layers of 12.5mm with 2 tubes of greenglue hope someone can point me in the right direction