Originally Posted by mom-6
There is an insulation board that is a dense foam about 3/8"(?)thick. You can find it at Lowes, Home Depot or the like.
There are different thickness of "rigid foam board", different manufacturers and therefore different colors. Some are pink some are blue. See "Extruded Polystyrene Foam" on this page
http://www.homeconstructionimproveme...lation-values/
Chances are you'll have to ask for it at those box stores and it may be outside for pick up/loading in your vehicle. Ask to go out and see it so you know what you're paying for first.