I will shortly be insulating a new pitched roof (single storey kitchen extension) using between-and-under PIR insulation - 100mm Celotex between rafters, 50mm under.
What is the best method of fixing the plasterboard to this afterwards? And how about the fixing of the 50mm Celotex - whats the best way there?
In the past I've used some plastic insulation hammer-in fixings (they had a big circular head), and then some really long plasterboard screws. The long screws were a cold bridge, thus defeating the purpose of the plastic fixings, and the plastic fixings kind of got in the way of the PB - they protruded from the insulation by about 3-5mm. This method was a pain.
What is the best method of fixing the plasterboard to this afterwards? And how about the fixing of the 50mm Celotex - whats the best way there?
In the past I've used some plastic insulation hammer-in fixings (they had a big circular head), and then some really long plasterboard screws. The long screws were a cold bridge, thus defeating the purpose of the plastic fixings, and the plastic fixings kind of got in the way of the PB - they protruded from the insulation by about 3-5mm. This method was a pain.