It might be easier to list the places you don't need to use GREAT STUFF™ Insulating Foam Sealant. Anyplace air gets in, GREAT STUFF™ keeps it out. And what a difference it can make. The U.S. Environmental Protection Agency estimates that homeowners can typically save up to 20 percent on heating and cooling costs by air sealing and insulating with spray foam. And you can air-seal your home in only a couple of hours with several cans of GREAT STUFF™.