 spray foam is sprayed from a gun and readily sticks to most surfaces, expanding to provide a highly effective seal. Reeves says medium-density spray foam has a higher R-value (i.e., insulating value) per inch than fiberglass or cellulose. But of course, Katz says, as with everything else, spray foams can be (and sometimes are) poorly installed and therefore don’t always perform as advertised.
Spray foam does have its disadvantages. It can cost more than four times as much as fiberglass or cellulose, installed, and it can be a nuisance to install. Michael Chandler of North Carolina–based Chandler Design-Build describes what can happen if proper precautions are not taken: “As the foam is sprayed, small droplets of foam end up in the air. This stuff gets in your hair, in your skin, and on your clothes.”
Moreover, although there are no published reports of health effects resulting directly from spray foam, the product does contain isocyanates, and unprotected exposure to this class of chemicals may cause asthma, lung damage, respiratory difficulties, and eye and skin irritation.18 Spray foams also contain flame retardants, most commonly tris(1-chloro-2-propyl) phosphate, a mild skin and eye irritant.19
Professional installers wear personal protective equipment to prevent exposure to foam droplets, Reeves says. But Chandler says that is not always true of workers who come in after the spray foam has dried to shave it down to a flat surface. Despite industry recommendations, “the people doing the shaving often don’t even wear a dust mask,” Chandler says.
Toward Better Retrofits
To ensure energy-efficiency retrofits provide a net benefit for occupants, the DOE is developing a set of voluntary guidelines for workers involved with weatherization assistance and home energy upgrade program activities.20 The guidelines will outline steps and specifications to ensure various types of retrofit jobs are conducted properly as well as essential skills contractors must have to perform the work. The guidelines are expected to help state weatherization programs choose qualified contractors to perform the work in homes. They also will help trainers provide appropriate content for an energy-efficiency retrofit workforce that is expected to grow in coming years.
In a related project, the EPA has drafted complementary guidelines that focus specifically on health and safety of workers and occupants in conjunction with energy-efficiency upgrades.21 Once finalized, these guidelines will provide steps contractors can take to ensure retrofit activities do not introduce hazards as well as detect and correct any indoor air quality issues that do arise during work. The EPA also plans to publish sample assessment tools for inspectors and contractors.
In the meantime, says Keith Aldridge, vice president of building science with Afdvanced Energy, the best way for consumers to ensure they get quality work is to search online for discussions about retrofit-related products and rely on word of mouth for advice on contractors.
References and Notes
1. DOE. Energy Efficiency Trends in Residential and Commercial Buildings. Washington, DC:U.S. Department of Energy (2008). Available: http://tinyurl.com/5ub5rzw [accessed 11 Jan 2011].
2. This figure is the sum of annual allocations listed on the DOE’s Weatherization Assistance Program website, available: http://tinyurl.com/2bv3324 [accessed 11 Jan 2011].
3. This figure is the average of figures listed on the DOE’s Weatherization Assistance Program Allocation Formula website, available: http://tinyurl.com/4o2ca93 [accessed 11 Jan 2011].
4. DOE. Weatherization and Intergovernmental Program—About [website]. Washington, DC:U.S. Department of Energy (updated 14 Apr 2010). Available: http://tinyurl.com/4p3pwbs [accessed 11 Jan 2011].
5. DOE. Audit Report. The State of Illinois Weatherization Assistance Program. Washington, DC:Office of Audit Services, Office of the Inspector General, U.S. Department of Energy (2010). Available: http://tinyurl.com/4sm9t4x [accessed 11 Jan 2011].
7. Texas Department of Housing and Communi