As part of a local council grant, I am getting my attic floor insulation (2 inch thick fibreglass) replaced with 4 inch thick insulation. It will lie between the joists, on top of the plasterboard which forms the ceiling of the rooms below.
I then plan on flooring the attic - not as a living space, but for storage.
As the joists are 2x4's, this means there will be no air space between the insulation and the flooring. From various articles I am unsure as to whether this is a problem, so my question is a 2 part one:
Do I need an air space between insulation and flooring in the attic? And if so, would adding joists on top of, and at 90 degrees to the existing ones and placing flooring on them be a practical solution?
I have read this question and I don't think it covers off my lack of knowledge in this area.