Plasterboard question

[cooperphilip]

In my loft my rafter's are 75 . I have left a 25mm air gap then 50mm Kingspan then foil back plaster board to prevent condensation.

Now I am not insulating the rafters underneath the big eaves i.e the shallow part of the roof. Now the wall's what come straight down from the eaves I have got the lagging roll insulation spare so I a using it in these walls. I have order's standard plaster board for these walls. Is this ok ?

 

[Alastairreid]

yes that will be fine, once you have fitted your insulation you will have to fit a vapour control barrier! 500 guage visqueen will suffice. then your plasterboard.

 

[cooperphilip]

I have got two rolls of roofing felt. IT is the cloth type felt so it is easy to use. Do you thin this is to use as it is waterproof ?