Adequate ventilation in a cold loft

[casademont]

I have a cold loft in a pitched roof. Insulation is over the ceiling not under the rafters.

I want to put 9mm plasterboard up under the rafters for aesthetics, I won't insulate between the rafters (100mm deep) as there is already insulation over the ceiling joists.

If I do this, do I risk cutting off the ventilation or is this only a risk if I were to insulate between the rafters?

Thanks

 

[Alastairreid]

The plasterboard will get damp as the attic is where the moisture from the house dissipates.

 

[^woody^]

for aesthetics

Wall paper would look better ( more variety) and just as useful.

 

[garyo]

I'd get a roll of white breather membrabe instrad and staple it up nice and tight. Easier to get through the loft hatch too. Presumably you're trying to stop the dust/cobwebs and get the light bouncing around a bit?