Spray foam insulation expands like magic as soon as you apply it. The foam sticks to everything, including skin and hair. And it must be popular, or you wouldn’t see so many cans of spray foam on display at hardware stores and home centers. Though the foam insulation that Dr. Energy Saver applies is slightly different than canned foam, the benefits are the same. Spray foam is the only insulation that seals as well as insulates, so it often eliminates the need for separate air-sealing steps. Because of its expanding nature, spray foam excels at filling gaps, cracks and cavities, eliminating the energy-sapping “voids” that can occur when installing other types of insulation. What’s holding foam back from being labeled “the perfect insulation?” You guessed it: cost. You can expect to pay 2-3 times as much for spray foam insulation as you would for fiberglass and cellulose.