The downlighters I have installed have the loft insulation simply pushed away from them to leave a gap. Unfortunately the multi-legged inhabitants of the loft seem attracted by the warmth and are falling into the fittings where they collect on the glass plate, block the light and are slow roasted.
I'm thinking of placing clay plant pots above the fittings to keep the wildlife away and to stop the insulation gradually moving back. The question is, how much bigger than the light fittings do the plant pots need to be? Too small and the lamps are presumably going to