Spray Foam Insulation vs Fiberglass Insulation

  • Beginner

Spray foam insulation is used in many household insulation applications. It is used to help insulate the walls and tiny crevices that may remain when the framers are putting together the exterior framing of the home. Insulation of a home with spray foam is mostly done by professionals since it does require a certain level of experience and expertise to be able to apply it uniformly. The small sealing jobs, however, can be done by DIYers using aerosol cans of spray foam. Below are several different components that compare spray foam insulation to fiberglass insulation materials.


Spray foam insulation can be expensive. It is usually anywhere between 20 and 30% more expensive to purchase and utilize than fiberglass insulation.


Spray foam insulation can also cause a lot of extra mess in places you would rather keep neat and tidy. Unlike fiberglass insulation that rolls out in sheets, the spray foam is found in pressurized aerosol cans. It can be very easy to miss the target, and overspray other certain areas. Because of the precision needed when using spray foam, you can add too much spray inside the walls and the walls can buckle because of the excess foam insulation.

Fitting Around Small Spaces

Spray foam insulation is a great product to use when you need to insulate small areas and holes. It is much harder to use fiberglass insulation in little crevices and nooks or crannies. You can much easier fill the holes responsible for creating draft like situations in your home by using foam insulation rather than fiberglass pieces.

Environmental Qualities

Spray foam insulation tends to be a little more environmentally friendly as compared to fiberglass. When you install fiberglass, you will undoubtedly have particles of fiberglass floating in the air. In addition, spray foam is not a material that will encourage the promotion of mold or mold-like spores. Fiberglass, on the other hand, will hold in moisture and can create conditions favorable to mold and mildew.


Spray foam insulation is a little more durable than that fiberglass insulation. It will generally last longer than its fiberglass counterpart. You must understand, however, that there are a couple of different types of fiberglass insulation. If you are using fiberglass that is held in rolls or batts, then it will generally last longer because it will not settle or flatten. If instead, you are using a type of fiberglass insulation that is loose-fill type insulation, it may not last as long.

Controlling Sound

Fiberglass is a much better product when you want to control the sound in between two adjacent rooms. Spray foam insulation will become hard and hollow, whereas fiberglass can be packed in between the walls of two rooms and can help to muffle noises that come from one room.

Specialized Purpose and Use

Spray foam is not as great of a material when you are looking to insulate things like your roof, your air ducts, or your pipes. For these applications, you are better to opt for fiberglass insulation.

Fire Safety

Fiberglass insulation does not generally promote fire or help a fire to move from room to room because it is made from sand and recycled glass. That being said, some of the facing used with fiberglass is combustible and should be used in appropriate locations. Spray foam insulation behaves much the same way as fiberglass and resists fire but does not fully protect you and your home.