A closeup of fiberglass insulation in a wall

Fiberglass insulation is one of the most popular types of insulation on the market. It is both affordable and effective as an insulator.

There are two common types of fiberglass insulation: batts and loose-fill. Both have different uses and features that make them valuable to homeowners. However, the cost and effectiveness of the insulation vary depending on the type of fiberglass insulation you choose. 

As you research the different types of insulation, it is essential to look at several factors, including its R-value, lifespan, ease of installation, and more. 

This article will compare the pros and cons of fiberglass insulation and look at the different types of insulation and where they are most impactful.

What is Fiberglass Insulation? 

To make fiberglass insulation, manufacturers weave very fine strands of glass together. It is then built into layers or small particles, depending on the insulation being made. As a result, fiberglass is a material that is durable and dynamic in its uses.

Different industries use fiberglass to construct everything from bathtubs to boats to roofing materials, and of course, insulation. Because of its universality across industries, fiberglass is one of the most popular insulation materials. In addition, it is a type that offers the most “bang for your buck.”

Its commonality makes it easy to mass-produce, so it is on the cheaper end for insulation materials. Additionally, it is still reasonably effective at insulating your home. It also can save you on costs because you can install rolled fiberglass insulation as a DIY project. 

Types of Fiberglass Insulation

There are two main types of fiberglass insulation—batts and loose-fill. Both are unique in their construction and uses. 


When you purchase fiberglass batt insulation, it will be in long rolls of layered fiberglass. The insulation is a structured material, and you cannot alter it.

A picture of un-faced pink fiberglass batts in the wall, with a man installing it

When unrolled, batts fiberglass resembles a thick blanket. This shape fits nicely in walls, but you can also install it in attics. It has an R-value of 3.1 to 3.4 per inch of thickness. One of the benefits of batts fiberglass insulation is its ability to be layered to create a higher R-value. 


The second standard type of fiberglass insulation is loose-fill, an unstructured form of fiberglass insulation sold in bags.

Typically, loose-fill insulation is most effective in attics; however, homeowners can also blow it into walls. Again, because stores sell it in bags, there is a lot of flexibility in where and how homeowners install loose-fill fiberglass insulation.

Loose-fill fiberglass insulation is shown in a wall before the drywall is hung

Loose-fill in an attic has an R-value of 2.2 to 4.3 per inch of thickness. In a wall, it has an R-value of 3.7 to 4.3 per inch of thickness.

Contractors typically opt for loose-fill fiberglass insulation to ensure its safe installation. Additionally, many installers will put a plastic sheet over the insulation to act as a vapor barrier and prevent the insulation from shifting. 

Rigid Fibrous or Fiber Insulation

There is a third type of fiberglass insulation, but this type has a specialized use.

Rigid fibrous insulation is meant for areas with extreme heat, such as around HVAC units and ductwork. Contractors do not install it in the walls or attics of a home.

This insulation has an R-value between 4 to 5 per inch of thickness and should only be installed by a professional. 

Benefits of Fiberglass Insulation

Fiberglass has numerous benefits. When choosing a type of insulation, it is essential to know both the benefits and challenges of the insulation you are researching. 


Fiberglass is very cost-effective, which is one of the reasons it is such a popular insulation material. The cost of insulation is usually between $0.40 and $0.50 per square foot. 

While the cost of the material is cheap, there are other costs to consider when installing insulation, such as labor and other job supplies. Considering all of this, the average price per square foot is between $1.87 and $2.97 when installing batt insulation. So for the installation of batt insulation in a 1,000 square foot ceiling or attic, the total cost could range from $1,872 and $2,966. 

Loose-fill insulation is cheaper because contractors use a blower for installation and the estimated labor time is lower. The estimated cost per square foot to install loose-fill insulation in a ceiling or attic ranges from $1.18 to $2.04. For a 1,000 square foot area, the total cost would be between $1,181 and $2,035. 

The cost above does not include the removal and disposal of old insulation. Overall, fiberglass insulation is a very affordable insulation solution. It is much cheaper than other types of insulation. 

Long Lifespan

In addition to being cost-friendly, fiberglass insulation has a reasonably long lifespan, typically around 50 years. Other common types of insulation only have a lifespan of maybe 10-30 years. Having a 50-year lifespan is a huge benefit, especially when combined with the cost-effectiveness of fiberglass insulation. You won’t have to pay to replace it every 10 or 15 years. 


Fiberglass insulation is made from recycled glass, making it incredibly eco-friendly. Whether it is batt style or loose-fill, manufacturers use recycled materials to make the insulation. Fiberglass is one of the only eco-friendly insulation options. 


Unlike some types of insulation, fiberglass insulation will not burn, meaning if there is a fire in your home, the insulation does not make the fire worse. Instead, its fire resistance makes it a valuable addition to homes. 

Challenges of Fiberglass Insulation

You also must consider the challenges when choosing fiberglass insulation for your home. These disadvantages may not be deal-breakers, but you should take them seriously when making the best choice for your home. 

Health Hazards

It is critically important to wear correct personal protective equipment (PPE) when handling or even being around fiberglass insulation.

It can irritate the skin if touched and cause severe lung damage if you inhale any particles. These particles are not just present during the installation process but well after contractors complete installation.

Fiberglass insulation being installed in the underside of a home attic ceiling, showing a beige fiberglass batt

If you are near or handling fiberglass insulation, wear a proper face mask, gloves, long sleeves and pants, and safety goggles. 

Does Not Act as a Vapor Barrier

On its own, fiberglass insulation does not act as a vapor barrier, meaning it does not naturally repel or prevent moisture or water from infiltrating your home. Therefore, adding a vapor barrier will be an additional cost on top of the insulation installation price. 

R-Value Decreases Over Time

Due to the nature of fiberglass, it tends to sag and settles during its lifespan. As a result, the efficiency of the insulation decreases.

In addition, as the age of the insulation increases, its R-value will drop, and it will not be as effective as it was at the beginning of its life. 

Does Not Create a Seal

Batt insulation does not create a seal to prevent unwanted airflow through edges or cracks of rooms. Instead, installers lay it down like a blanket. Because of this, it does not seal to anything, which can cause inefficiencies where you are insulating. While it may not be large areas that are not covered, those small inefficiencies can significantly impact over time. 


Fiberglass is an eco-friendly and cost-effective insulation solution. It comes in batt and loose-fill varieties. Homeowners typically use batt-style insulation in walls and loose-fill in attics; however, both types are appropriate for various installation purposes. 

There are several advantages and challenges of fiberglass insulation. It is cost-effective, efficient, and eco-friendly. Additionally, it does not burn. On the other hand, it can be unsafe to handle and does not act as a vapor barrier, which can be an added cost if needed. Additionally, the efficiency of fiberglass decreases over time.

One Comment

  1. I like that you mentioned how fiberglass insulation has a reasonably long lifespan, typically around 50 years. We are currently overhauling our house and we are thinking of installing new insulation. We should probably ask for a fiberglass insulation installation service since it seems like a pretty good option.

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