Hi,
Just finishing of the insulation of a newly installed roof. It requires 100mm celotex between the rafters, 40mm celotex under the rafters, a polythene vapour check and, finally, 12mm plasterboard.
With respect to the vapour check, is this just a standard polythene sheet of a certain thickness or a special item?
Also, is it ok to use standard zinc coated screws to fix the plasterboard as these need circa 70mm long to screw through the pb and 40mm celotex.
thanks in advance.
Just finishing of the insulation of a newly installed roof. It requires 100mm celotex between the rafters, 40mm celotex under the rafters, a polythene vapour check and, finally, 12mm plasterboard.
With respect to the vapour check, is this just a standard polythene sheet of a certain thickness or a special item?
Also, is it ok to use standard zinc coated screws to fix the plasterboard as these need circa 70mm long to screw through the pb and 40mm celotex.
thanks in advance.