The use of spray form insulation in homes declined in recent years after a long period of increased use, according to a recent survey by Home Innovation Labs.

The product testing and market research laboratory, established in 1964 as part of the National Association of Home Builders, surveyed 1,300 home builders across the United States. While use of spray foam insulation increased from three percent to 11 percent between 2008 and 2012, it fell back to eight percent in 2013. The use of this kind of insulation declined in each of the four census regions; it was also used less frequently in all areas of the home including floors, roofs, and walls.

"While we recognize that a one-year data shift does not constitute a trend in building product usage, this may be signaling a change in the home insulation landscape," Home Innovations Labs says in a summary of the survey.

Fiberglass insulation, which accounted for 90 percent of cavity insulation in new homes in 1994, regained some popularity in recent years. The use of fiberglass batt insulation increased from 54 percent in 2012 to 55.4 percent in 2013, while fiberglass blown increased one percent in the same period, from 18.1 percent to 19.1 percent.

Other insulation types also saw modest increases between 2012 and 2013. The use of rockwool increased from 0.9 percent to 1.1 percent, foam board use went from 5.6 percent to 5.7 percent, and other types of insulation increased from 1.1 percent to 1.3 percent. The use of cellulous insulation declined slightly, from 9.4 percent to 9.1 percent.

The survey concluded that the growth in spray foam use between 2008 and 2012 was likely a result of its convenience in bringing insulation to confined areas. The Department of Energy says spray foam insulation is resistant to air or water intrusion. The insulation will also expand as it cures, providing a tight seal in the space.

Home Innovations Labs says the increased R-value of spray foam insulation allows builders to meet home energy codes more easily and provide insulation in areas that are difficult to reach, such as wall cavities. The Department of Energy notes that spray foam insulation has to be put in by a professional and is more expensive than traditional batt insulation, but can save money in the long run by reducing construction time and making a home more energy efficient.

The survey found that spray foam insulation was most popular in luxury homes. These residences were twice as likely as move-up homes to use spray foam insulation and four times as likely as starter homes. However, builders who construct fewer than 10 homes a year were twice as likely to use spray foam insulation as larger builders, and builders of single family homes were also more likely to use the insulation than multifamily builders.

Home Innovations Research Labs posits that the decline in spray foam insulation is part of an overall trend among builders to use fewer and less expensive materials when constructing homes. Less expensive options became more popular in other areas as well, including decks, flooring, and windows.

The organization says other reasons for the decline in spray foam may include changing homeowner demographics and the use of alternative methods of increasing R-values and tightening air seals. Spray-on sealants, foam board wall sheathing, and energy trusses are all options that give similar benefits to spray foam insulation. Since spray foam insulation is more prevalent in high-end homes, it is less common as multifamily rental properties now account for one-third of all new home construction.

Thirty percent of the builders who took a Home Innovation Labs survey in 2013 indicated that they had used spray foam insulation in their projects but had stopped using it in current construction. The organization says builders often indicate that fiberglass options are more cost-effective and easy to install.

The Department of Energy says fiberglass insulation comes in widths that correspond with the standard spacing of wall studs, rafters, and floor joists. It can also be cut and trimmed to size.

However, fiberglass insulation is not as effective as spray foam insulation unless it is sufficiently thick. The Department of Energy says standard fiberglass batt has an R-value of 2.9 to 3.8 per inch, while the R-value of higher quality fiberglass options can reach 3.7 to 4.3 per inch. Green Building Advisor says closed cell spray foam insulation has an R-value of 6.5 per inch.

Home Innovation Labs says in its summary of the survey that it is "virtually impossible" to determine future trends of insulation use without extensively studying all of the factors that have a role in selecting a product. However, the organization says it will be less likely that a specific type of insulation will see advances as significant as that made by spray foam insulation between 2008 and 2012.

"The insulation market is highly competitive, and any ground gained by specific product categories within the market will be harder won than gains made in the past," the summary concludes.