Spray Polyurethane Foam (SPF) is one of the fastest growing products in the building and construction industry. The History Channel’s Modern Marvels segment on insulation described it as “the secret weapon on energy consumption .” Building professionals are using spray foam more readily than ever before as advances in product application and composition increase the product’s versatility. It can be used on roofs, in wall cavities, and on foundations, to name just a few areas of application.
Although SPF is in vogue for residential energy retrofits today, the technology has been around for over 50 years. In Germany, Mr. Otto Bayer worked with polyurethane polymers, giving birth to the first use of foam, which he introduced to the world in 1937. Later, it was brought to the United States for additional research and development. Further advancement in the 1940s led to its use in military and aviation industries. But it wasn’t until the 1950s that polyurethane would be used as home insulation.
In 1952 Mr. Walter Baughman created the “Blendometer." The Blendometer revolutionized the use of spray polyurethane foam. The Blendometer was a device capable of mixing the chemical components required for the creation of polyurethane foam. The machine’s proportioning values mixed the perfect blend to create the expanding foam. Although Mr. Baughman’s creation led to some of the first applications of foam in homes, it wasn’t unit the 1960s and 70s when advances in spray gun nozzles made it more practical for spraying polyurethane foam in homes.
Today, polyurethane foam products are pushing the thermal envelope. Manufactures are engineering creative ways to inject these products into wall cavities through holes as small as a half inch. SPF roofs are becoming increasingly cost effective alternatives to roof replacement. Since these applications have the capacity to seal, insulate, and serve as white reflective surfaces, they are steadily gaining market share compared to conventional roof replacements. Efficiently applying the product is an art; the spray gun becomes the brush and the roof becomes the artist’s canvas. The technician fills cracks, carves out valleys, and creates troughs to mitigate water run-off.
This “super material’s” density has an R Value that can be nearly twice that of traditional insulation, has sound detonation capabilities, increases a home’s ventilation control, and some applications can add structural integrity. Closed Cell foam technology has been attributed with increased resistance to mold and moisture
So why isn’t the “secret weapon on energy consumption” readily used for retrofit applications? One barrier is cost, which has been shown to decrease as contractors achieve economies of scale, technological advancements, greater efficiencies in product usage, and better material storage techniques which drive costs down. Increasing numbers of people are turning to SPF applications. Just as the market pushed the need for a $199.00 Netbook, the market is driving costs down for foam technologies.
Although the product is revolutionizing the insulation industry, it’s not without controversy. A second barrier to the product’s use in residential retrofits is health risks associated with its application. Although the EPA has concentrated on the potentially hazardous side-effects when applying the product, a significant amount of research is still needed on “off gassing” and VOC emission for interior applications.
The EPA has expressed the following on SPF application:
“Spray polyurethane foam (SPF) is a widely used and highly-effective insulator and sealant; however, eye, skin, and inhalation exposures to its key ingredient, isocyanates, and other chemicals in SPF products of concern in vapors, aerosols, and dusts during SPF installation can cause:
During SPF installation, residents and other unprotected building occupants should vacate the premises until after the foam is applied, cured, trimmed, and the area has been thoroughly cleaned to eliminate any residual isocyanates and ventilated. Some manufacturers recommend 23 to 72 hours before re-occupancy for two-component applications and 6 to 12 hours for one component foam applications, but re-entry time is dependent on product formulation and other factors .”
- Asthma, a potentially life-threatening disease
- Lung damage, Respiratory problems and other breathing difficulties
- Skin and eye irritation
- Other potential adverse health effects
Although the EPA appears to focus on health effects “during SPF installation,” few testing standards exist on testing the material for “off gassing.” Additionally, little data is available for the injection of foam in encapsulated wall cavities. California, Canada, and the European Union have adopted regulation thresholds for VOC off gassing, but few standards currently exist at the U.S. national level. Although there is a lack of VOC regulations specific to SPF, responsible manufacturers seeking green credentials are testing their products using the most aggressive standards.
Cutting edge foam products and applications are becoming increasingly available with the potential of radically changing the energy retrofit industry. The WAP network needs to stay abreast of these innovative technologies and their applicability for weatherization.