I have recently brought a property which has a old conservatory / extension at the back with a flat roof. I want to put up a new plasterboard ceiling in this room to replace the cardboard tiles which are on the ceiling. Upon removing the tiles I have found:
* Paper layer with one side film (looks like old radiator paper)?
* Wool Insulation maybe 100mm thick
* No ventilation!
The gap between the end of the joists and the decking is 155mm (top of slope) to 105mm bottom end (bottom of slope).
I now need to decide what is best to do.
1) Do I add vents into the soffits for ventilation? But due to the limited joist size I would probably need to forfeit having any insulation.
2) Or do I carry on with no ventilation and stuff it with insulation? (As it was already).
The roof is NOT in bad order considering its age and lack of ventilation but I would like to do what I can to improve its life span and reduce potential problems for myself in the future.
Advice gratefully welcomed!