Spray Foam: Is It Greener than Other Insulation?


Spray foam insulation is one of the newest forms of residential and commercial insulation. It is often hailed as the most effective and greenest insulator on the market, greatly reducing energy losses and saving homeowner's money.

Spray foam may save a lot of energy from being lost, but when one takes into consideration the life-cycle from manufacturing to installation, is it really the most eco-friendly option to insulating your home?

This material is made up of a polymer (such as polyurethane or modified urethane) and a highly reactive foaming agent. The two components are kept separate until they reach the nozzle of the spraying machine when they quickly react creating a material that can expand up to 100 times its original size.

Ideally the spray is applied directly in between wall studs as the last step before installing the drywall. In the case of retrofitting, the insulation can be applied through holes and then it expands to fill even the smallest nooks and crannies making an air-tight seal and thus eliminating the escape of air, energy, and money.

There are two types of foam insulators: open-cell (isocyanurate) and closed-cell (polyurethane). Open-cell types allow for the infiltration of vapor, while the closed-cell provides superior insulation and serves as a vapor barrier.

Both types have high R-values. R-value is the measurement of thermal resistance used in the construction industry today. The higher the R value (numberical value) a material has, the more effective the material is as an insulator. Foam insulation has a much higher R-value than most insulators. In fact, it has twice the R-value per inch than traditional fiberglass batt insulation.

What makes it environmentally friendly? First and foremost, it fills every imaginable space trapping the heat, cool air, or moisture from escaping through cracks. It also cuts down on wasted energy by 20-40%. So by using insulating your home with this energy-efficient material, you are using less energy to begin with.

Also, some brands of foam are made from agricultural based materials and use high levels of reusable materials. While the amount of energy saved in your home and business is remarkable and very environmentally friendly, when you consider the whole process of manufacturing to installation there are some non-green practices involved.

Many spray insulators often use HCFCs or HFCs as blowing agents. Both are strong greenhouse gases, and HCFCs are believed to deplete ozone. Also, the installation requires handling of hazardous chemicals that pose a concern to the environment if there happened to be a spill during production or transport. People attempting to reduce the use of fossil fuels might be disappointed to learn that spray foam insulators are made from petrochemicals.

Is spray foam the greenest option? There are other insulators including traditional fiberglass batt, loose fill cellulose, and reflective insulators. Fiberglass batt is frowned upon by environmentalists as it is made from petrochemicals and uses HCFC's as blowing agent which has ozone depletion potential. These environmental cons are not unique, but fiberglass does not initially save as much energy.

The makeup of cellulose is environmentally preferable being made up of 80% recycled newspaper and contains no petrochemicals. However, it also does not insulate the home as well. Reflective insulators are also eco-friendly in their makeup, however, it is only highly effective in warm climates. In colder climates it must be combined with other insulators.

Spray foam has some environmental concerns during production and transport; however it causes property owners to use far less energy to heat or cool their building. So is it the greenest insulator option? Each user must make that judgment call for themselves but experts suggest that overall, spray foam is the most effective and environmentally friendly insulator.

By: Andrew Stratton