With spray foam insulation, one application can do it all. The space is sealed airtight; R-Values are installed at a high rating; and structural strength is provided wherever the product is installed. As it is, spray foam insulation is a premium-priced product, but overall, the project investment is worthwhile. The significant energy savings (winter and summer) will often be enough to create a cost effective "payback" period, giving the project a very favorable cost-benefit outcome. Indeed, spray foam insulation doesn't require replacement or replenishment, like many other products.