Spray Foam vs Fiberglass Insulation: Breakdown Analysis

Fiberglass insulation is instantly appealing because it’s typically cheaper, but spray foam often works better in colder climates. This is just one thing to consider when weighing your options with spray foam and fiberglass. These two types of insulation are both considered standards when it comes to insulation used for construction/building purposes. In order to help you decide which option to consider for your specific needs, take a moment to develop a deeper understanding of these two insulation products.

Spray Foam Insulation

Spray polyurethane foam (SPF), or simply spray foam insulation, is a spray-applied plastic product designed to seal cracks and gaps and form a solid air barrier. This type of insulation comes in two forms: open and closed cell. Open-cell SPF is typically used to create an air barrier. Close-cell SPF, on the other hand, is typically capable of creating vapor, moisture, and air barriers.

What Spray Foam Is Made Of

There are two main material components of spray foam insulation: isocyanate and polyol resin. When these materials combine, the resulting mixture is capable of expanding to about 30-60 times its liquid volume. The foam created by the chemical mixtures used in today’s spray foam insulation is generally considered environmentally safe.

What It Looks Like When Fully Installed

Once spray foam is applied and fully installed, it will form a solid surface. It’s usually a bright white color since this is what the color of the mixture is when it’s applied. The cured or hardened form of spray foam has what could be described as a pockmarked appearance because of natural imperfections that develop during the curing process, but this doesn’t affect insulating properties.

How It’s Installed

With the installation of spray foam insulation, you’ll use a portable kit if you’ll be doing the installation yourself. Professional contractors use a truck-mounted unit. A kit usually includes:

  • A hose
  • An applicator gun
  • Nozzle tips
  • Goggles and gloves

You’ll also need to wear a full protective suit and a respirator to protect your lungs. Make sure surfaces are completely dry before applying the spray mixture. It’s also a good idea to do a test spray in the box that kit came in to make sure everything is working as intended. The general recommendation with spray foam application is to frame the edges of the cavities to ensure all gaps are filled before filling in the inner sections. A curry comb or other scrapping tool can be used to remove excess foam.

It usually takes 1-2 hours to apply spray foam to typical home interior locations like attics and basements. If the job is bigger, however, it may take the better part of a day to finish up.

Benefits of Spray Foam

  • Creates an air seal
  • Has the highest R-value – referring to a measure of a particular material’s insulating effectiveness*
  • Rodent proof
  • Mold proof

* Closed-cell spray foam has a higher R-value than the open-cell version.

Fiberglass Insulation

A common choice for construction insulation throughout North America, fiberglass insulation is considered a highly versatile material since it can be applied in many areas of a home or business structure. It’s often available as pre-cut batts and rolls or blankets, but it also comes in blown-in loose-fill form, which is an alternative to cellulose.

What Fiberglass Insulation Is Made Of

Fiberglass insulation is so-named because it’s made of tiny glass fibers. There are several different materials that may be used to produce fiberglass insulation, with the main ones including silica sand, limestone, and soda ash. Some manufacturers add an assortment of other materials and chemicals, some of which enhance desired protections against fire and other possible sources of damage. Discontinuous glass fibers are used to create the form of fiberglass insulation typically used for construction or home insulation purposes.

What It Looks Like When Fully Installed

Once fully installed, fiberglass insulation has a solid-but-fluffy appearance if you use batts or rolls. It’s sometimes described as having a cotton-like appearance. The batts are also commonly referred to as “the pink stuff” because of the color a popular manufacturer uses. The blown-in version has a fluffier appearance when fully installed.

How It’s Installed

With the installation of fiberglass insulation, you’ll need to wear a dust mask, safety glasses, and gloves since the fibers can irritate skin. No special machinery is required. However, if you use the blown-in version of fiberglass insulation, you’ll need a piece of equipment called a blower. With batts, place each one to fit and make the necessary cuts.

As for how long it takes to complete installation, it could take a few hours if you’re just doing a fairly small or confined area. It’ll take a bit longer if you’ll be replacing older or damaged insulation with new fiberglass insulation. For an entire building, it could take a few days or more if you spread the work out.

Benefits Of Fiberglass Insulation

  • Least expensive type of insulation
  • Ease of installation