NIJAC caters to a savvy clientele – captains of industry, who understand their business and the
elements they need to succeed. You already know that selecting the correct insulation is
paramount to paying the lowest heating and cooling costs, as well as protecting the contents of
your buildings. All that remains for you to do is decide which type of insulation to install.
This article will explain how spray foam is usually superior to blown-in insulation. But before we
begin elaborating spray foam’s relative merits, let’s briefly define the two major types of
What Is Spray Foam Insulation?
Spray foam insulation is a concoction of isocyanate and polyol resin. Without detailing their
chemical properties, these substances react to blending and exposure to air by expanding and
hardening to create an airtight seal. They effectively insulate any surface they cling to, be it
vertical or horizontal.
Spray foam itself is available as two types of insulation: open-cell and closed-cell. Open-cell
spray foam insulation creates a more porous structure, whereas closed-cell spray foam
insulation is often denser because its component pockets totally encapsulate themselves before
solidifying in place.
What Is Blown-In Insulation?
You have no doubt encountered fiberglass insulation in the past. The fiberglass-reinforced
plastic matrix is often installed as large batts which resemble blankets of pink cotton candy.
Polyurethane foam fiberglass may also be applied as an adhesive spray. The installation of
blown-in fiberglass looks very similar to the application of spray foam, but the two types of
insulation possess markedly different properties.
Spray Foam Typically Offers More Advantages Than Blown-in Insulation
The mere fact that blown-in insulation exists and is continually installed at residential,
commercial, agricultural and industrial buildings throughout the country suggests that it poses its
own advantages. Indeed, under certain conditions fiberglass insulation may be the superior
choice for a given project.
That said, spray foam typically outclasses blown-in insulation in several aspects of its
performance. In most cases it is a more effective insulator, longer-lasting, and more economical.
Furthermore, the waterproof barrier it forms offers a greater degree of protection against the
● Greater R-value. An insulation’s R-value measures how effectively it does its job of
retaining heat. Spray foam possesses higher R-values than blown-in insulation, with
closed-cell foam generally offering the higher R-value of the two types of spray foam.
Whereas blown-in insulation offers an average R-value of 2.45 per inch, closed-cell
spray foam consistently offers 3.5 per inch; closed-cell spray foam consistently achieves
6.5 per inch!
● Waterproofing. Though it does provide insulation, blown-in fiberglass cannot create a
moisture-repellent barrier like spray foam can. In effect, spray foam provides an
altogether added advantage when the property owner seeks to waterproof their property.
● Potentially cheaper. Closed-cell foam insulation may cost as much as $2 per square foot
once installed. This can be double the cost of the most expensive blown-in fiberglass
insulation on the market. However, open-cell spray foam installation can cost about 10%
less than even the cheapest blown-in insulation. Ultimately, the cost of installing any
type of installation hinges upon the type of project and must be considered on a case-by-
case basis. In many situations blown-in fiberglass may actually be the more economical
● Superior lifespan. Fiberglass deteriorates over time, thus losing its R-value. Undisturbed
blown-in insulation can often last for as long as 100 years, although its brittleness and
vulnerability to water infiltration mean that fiberglass can easily become damaged after
around 25 years. Resilient spray foam, on the other hand, cannot lose its efficacy over
time and may theoretically last forever (although 80 years is a more realistic maximum
expectation). Spray foam thus poses significant savings as it may spare you from having
to reinstall insulation in the near future.
For these reasons, if you were to select a single type of insulation for all your properties moving
forward, spray foam would be the better choice. But as we indicated earlier, blown-in insulation
still offers great value depending on the client, their properties, their expectations for their
insulation and their budget.
If you would like to make the best business decisions regarding your future insulation needs,
you would do well to count on an expert’s advice. We welcome you to reach out to NIJAC today
for precisely that guidance! With just a little more information about your properties’ unique
insulation needs, we’ll be able to inform the correct choice as to how you should move forward.