Discovered that the attic access hatch isn’t insulated, which honestly isn’t surprising given when it was built. No ladder system. I’m working on cutting up some foam boards to glue to the backside. Hopefully it will reduce how much is radiated through this barrier.
Its a good first step, but the r value of reflectix isnt nearly as much as foam board or fiberglass. Foam board has a reflective coating on the outside that will do the same thing (reflecting IR radiation). But if you have some lying around and it works, then it works.
As thick as possible polyiso will probably be your best bet. 1" is R6
Try to get a total of r40.