Two alternatives to rolls of fiberglass insulation are blow-in and spray foam insulation. While it would be incorrect to say that one is better or worse than the other, your best option will depend on your insulation needs. 

As you learn more about how these two types of insulation differ, you’ll be able to determine which one will offer you the best benefits for your situation.

What to Know About Blow-In Insulation

Blow-in insulation is also called loose-fill insulation because that’s exactly what it does. Insulation installers use a machine and a large hose or tube to blow loose pieces of insulation into the open spaces in your attic or walls. 

Styrofoam, cellulose, or fiberglass make up the loose pieces of insulating materials. The loose fill is often treated to be fire-resistant.

Since this method involves using loose pieces of insulation, you can layer as much of the product as you think your home needs. This allows you to control the R-value of your insulation — or how much heat-flow resistance the insulation has. 

This type of insulation is long-lasting and durable. You shouldn’t need to replace it for 25 years on average.

How Is Spray Foam Insulation Different?

Spray foam insulation involves using equipment to spray a thick foam onto walls or attic floors. The foam will expand and harden within a short period of time, forming a thick barrier. 

One noticeable way it differs from blow-in insulation is the installation process. Because wet chemicals make up the foam, it gives off fumes that are hazardous to inhale. Professional installers will wear protective equipment during the installation process. Additionally, you will have to leave your home until the foam hardens.

Spray foam can also fill smaller gaps than loose-fill insulation. This makes it ideal for insulating around plumbing pipes, wires, and other equipment. Spray foam lasts much longer than other types of insulation, and you may not need to worry about replacing it for up to 80 years. 

How Can You and Your Insulation Installers Choose the Best Option?

There are several factors to consider when choosing the best type of insulation for your home. It can help to talk to your installation contractor since they can tell you more about each type of insulation. Generally, there are a few main factors to consider in picking the right insulation, such as those listed below.

Upfront Cost

Although you might consider how longevity will affect the value of your insulation, you should also look at the upfront costs. 

Loose-fill insulation is cheaper than spray foam when you choose recycled materials for the loose fill. Your cost will also depend on the amount of space you need to fill, so obtaining an estimate can give you more precise information.


Your biggest concern may be the R-value of your insulation. Spray foam provides a higher R-value, which means you’ll need less of it to protect your home. While loose fill does have a lower R-value, it’s also cheaper. This means you can add additional layers at a lower cost to provide an equivalent level of protection.


Both types of insulation are good for filling small spaces. However, spray foam can get into tiny cracks and crevices that loose-fill would only cover. Spray foam can also insulate your walls, making it easier to cover small spaces around window frames, vents, and similar obstacles.

If you’re having trouble determining which type of insulation you should use, contact an installer in your community. They can help you determine whether blow-in or spray foam insulation will provide you with the best protection over a longer period of time. They can also save you time and money by installing the insulation.