I had problems in 2013 to 2014. It was fixed after a lot of grief. In my instance, it was all to do with airspace.
The materials used were the same. The major difference has been to reduce the amount of air space, and so the roof is 4 inches lower than previously. This has removed the need for the long screws. The problem doesn’t seem to have had anything to do with dampness, cold deck or warm decks, or expansion joints. It seems to have been about the amount of airspace, what is in the airspace, and temperature changes. It is so peaceful suddenly.
Here is the explanation. I am not technical, but I do know that the problem was fixed, but the roof had to be rebuilt.
In simple terms, the new grp roof was originally built on top of the old boards. This is done sometimes so that it does not disturb the ceiling, possibly causing damage or cracks. The risk is that we must make sure that the screws have picked up the kingspan (foam installation) and the board. If this is not perfect, it may have been the cause of the noise.
There is another type of installation and this is to sit the kingspan in between your joists and then screw the boards down. This is what has been done now, and is the most common installation (probably referred to as standard). You still get the insulation and we know that the boards will not move.
