Hey.
When doing this yourself, it's pretty basic with a few things to keep in mind. Leaving a minimum 2.5cm gap for things such as not covering little white boxes with wires running in and out of them and exhaust/vents. As for the ducted outlets in the ceilings, I can have the batts go right up against them, no gaps. Right? Oh, and protective clothing
I've already started on re-doing it. The guys who installed my heating and cooling lifted some of the batts and put them in piles, and some may have been soaked in rain due to cracked tiles as water dripped through the ceiling. I understand that there should be no gaps; batts fit snugly in between joists and batt-ends should be butted together. Well, there is a section where I cannot apply insulation and that is where the indoor heating and cooling components are sitting on the joists.