It would actually be more effective to put the reflective stuff on the under side of the hatch since this would reduce its ability to radiate heat to your space. It would look terrible of course.
Actual insulation on the top is going to be the most effective.
It would actually be more effective to put the reflective stuff on the under side of the hatch since this would reduce its ability to radiate heat to your space. It would look terrible of course. Actual insulation on the top is going to be the most effective.