Spray foam insulation is sprayed on walls, roofs and other surfaces. It expands to fill every nook and cranny, creating an airtight seal and making your home more comfortable and energy efficient. It’s also easy to install around pipes and wires.
But the insulation’s rigidity and a lack of moisture barriers can make it susceptible to mold. And some spray foams contain chemicals that are toxic. The problem is so serious that Efficiency Vermont says a shortage of qualified weatherization experts and contractors is allowing contractors to cut corners when installing spray foam.
Generally, builders spray two inches of closed-cell spray foam in walls and three inches in roofs to meet energy code requirements. But the R-Value (the measure of an insulator’s ability to resist heat transfer) can vary widely, depending on climate.
Eco-Friendly Living: The Environmental Benefits of Spray Foam Insulation
It’s important to choose a green builder and ask questions about spray foam. Closed-cell spray foams are more expensive than open-cell, but they do a better job of insulating and create an effective vapor barrier so homeowners don’t have to apply a separate one themselves.
In addition, closed-cell spray foams can be injected between joists to add extra support and strengthen the structure of the building. Spray foam can also help improve indoor air quality by absorbing sound and keeping the noise from the warehouse below a customer service office from disturbing employees. Closed-cell spray foams can also be used in commercial buildings. The new HFO blowing agents, which are replacing HCFCs, have a global warming potential of 1, which is less than carbon dioxide’s.