Spray foam insulation comes in two different types - open-cell and closed-cell. When insulating your home you must decide which of these types of spray foam insulation you want to use. They each have their pros and cons, and your choice could make a big difference in the cost of insulation and the insulation’s performance.
Open-cell spray foam
Open-cell foam is a very light material that is designed to break or pop as the foam expands but before it sets, allowing pieces to be removed. Open cell foam is low density and can fill larger areas with less material, and it has a R-value of 3.5-4 per inch.
On a cost-per-R basis, open-cell is the more economical spray foam choice. However, it is not as effective as closed-cell spray foam. Open-cell is a more environmentally friendly option as well, which is a benefit for homeowners concerned about their environmental impact.
Closed-cell spray foam
Spray polyurethane foam, or SPF, is the main type of 2-part, closed-cell spray foam used by insulation contractors. Large-scale insulation jobs require special equipment as well as safety gear to protect the installer from chemical fumes during installation. When the foam cures and hardens just several minutes after application, it's completely safe for as long as it stays in place.
When properly installed, SPF creates a highly insulated building assembly that's also free of energy-wasting air leaks. Closed-cell is about 3-4 times as dense as open-cell foam, and it provides an R-value of 6-7 per inch.
