Spray Foam Insulation Vs. Fiberglass Insulation

Choosing the best insulation for your home is important for reducing your energy consumption, making your family comfortable regardless of the season and improving your air quality.

Just about everyone is aware of what fiberglass insulation looks like: it’s that pillowy, cotton candy-looking material that you’ll find in walls, the roof or attic crawl spaces. Made of thin spun threads of glass, fiberglass insulation has been a popular choice for decades.

Alternatively, spray foam insulation — a chemical foam that is sprayed into crevices where it hardens — has gained popularity over the years.

But which is best for your home? When looking into replacing your current insulation, spray foam can seem like a more beneficial option — after all, can the fiberglass insulation your grandma used really be the best option in the 21st century? However, the answer isn’t so clear-cut. Read on to learn more about spray foam insulation vs. fiberglass.

Pros and Cons of Spray Foam Insulation

Spray foam insulation is created when combining polyurethane and isocyanate. Because they are mixed as they’re being sprayed, the foam is pliable when sprayed, then quickly hardens.

The most common forms of spray foam insulation used in homes are open-cell and closed-cell formulations. The differences come down to the interior bubbles either harden as holes (open-cell) or are encased (closed-cell). For homeowners, it’s not necessary to know which is being used, but typically closed-cell is used in walls that lead to outside as it has a higher R-value (meaning it is better at reducing heat transference) and is better at dampening noise. Open-cell is usually used on interior walls where some heat transference and noise are less of a concern.

Pros of Spray Foam Insulation

• For those living in wet climates, spray foam insulation is good at keeping moisture out, although a moisture barrier is still recommended.
• Installation is fairly quick when done by an insulation expert. Once the required insulation thickness is determined, the installer can spray within the wall cavity where it adheres, expands and cures on its own.
• Correctly installed spray foam insulation is stable and cures into a hard mass so it won’t deteriorate, sag or settle and can last up to 80-100 years with minimal maintenance.

Cons of Spray Foam Insulation

• If too much spray foam is used, it can damage drywall while curing since there isn’t enough space for it to expand. Removing drywall and replacing it when the insulation is cured will help minimize this issue.
• Because spray foam insulation is made of chemicals, it produces volatile organic compounds (VOCs) that take time and proper ventilation to dissipate. VOCs can cause or exacerbate respiratory issues, especially in those with asthma and other illnesses, as well as headaches and nausea. Low-VOC spray foam is available, but there will always be a dispersal period for spray foam.

Pros and Cons of Fiberglass Insulation

Fiberglass is exactly what it sounds like: glass spun into thin fibers that are combined into sheet or loose fill. Fiberglass insulation works by trapping air within it, slowing the transfer of heat. The thicker the insulation, the better it works, so it can be used in just about any climate.

Pros of Fiberglass Insulation

• Because fiberglass is created in a factory and then delivered, there aren’t any VOCs that will need to be aired out after insulation.
• Fiberglass is installed as sheets, rolls or loose fill, making it easier for it to be installed without a professional, although it is still highly recommended due to the sensitive nature of insulation and potential personal harm.
• Fiberglass doesn’t expand, so it can be installed into spaces without having to remove drywall.
• Properly installed, fiberglass usually lasts about 80-100 years

Cons of Fiberglass Insulation

• Fiberglass insulation’s pliability means that it can sag, degrade and settle to the bottom of vertical spaces, so maintenance or additional insulation may be needed over time.
• Thin fibers of glass are still glass, making fiberglass insulation irritating to the skin and dangerous to respiratory systems if breathed in.
• Is fiberglass insulation safe? When properly installed and enclosed: yes. But easily accessible or exposed fiberglass insulation can be tempting for young children to play with or try to eat, which is obviously extremely dangerous.

Spray Foam Insulation Vs. Fiberglass Insulation Cost

Because both spray foam and fiberglass insulation work well in any climate and have their own benefits, cost can often be the determining factor.

Spray foam insulation comes off as less desirable when pure cost is the only consideration. The average cost of spray foam insulation is $2.75 to $7.50 per square foot, while the average cost for fiberglass insulation is between $0.30 to $1.50 per square foot.

Is Spray Foam Better Than Fiberglass Insulation?

In terms of whether one type of insulation is far and away better than the other, the answer is no. However, it’s important to understand the various aspects of your insulation options and consider how your insulation is getting installed, no matter what you choose. Turning to the experts, like those at City Wide Insulation, will make sure that whatever insulation you choose is installed quickly and correctly.