Step 1: You find white paint (preferably old, unwanted)
Step 2: Paint your roof. That’s it, save 20% on your bill if you started with a darker colored roof.
You will feel the difference on your feel almost immediately after drying and the attic temperature may drop as much as 20 degrees that very day! When you consider that my AC comes on much less often, the savings only compound over time.
My story: I painted the roof on my shed to test this idea and the temperature change was immediate (before the paint even dried). I had a 15 degree drop in the space the same day (image 95 degrees drops to 80 degrees with just a roof color change, that is what I experienced). It took two hours and about ten gallons of outdated used white primer paint. Worth it every time I walk in the shed! The house is next! 🙂