Fiberglass Insulation: Drawbacks And Alternatives

Carla Ayers6 minute read
UPDATED: July 25, 2022


Nothing ruins a warm and cozy afternoon more than a cold breeze from poor insulation. If your home is well-insulated, you probably don’t think about it often. But for those who live in homes with poor insulation, it might be on your mind and your to-do list.  

Insulation allows heat to stay in your home and the cold winter air from getting in. You can find fiberglass insulation in many homes today. Fiberglass rose to popularity in the late 1930s when an effective method of mass-producing glass fibers was discovered. After that, fiberglass could be found in boat hulls, fishing rods and, eventually, vehicles.

Fiberglass insulation has helped improve energy efficiency in the home but over time it was discovered that the microscopic fibers could be incredibly hazardous when inhaled or handled. There are other options you can use in your home, and we’ve compiled them here. Read on to learn more about safer home insulation alternatives.

What To Know When Shopping For Insulation

Don’t let shopping for insulation be overwhelming. We’ve done some of the heavy lifting and pulled together insulation terms to help you better decide what you might need and what your options are.


R-value stands for the resistance the material has to heat transfer. The higher the R-value of your insulation, the more efficient it’s going to be. Depending on where you live in the United States, there are different building code requirements for the R-value needed. In colder climates, you’ll need a higher R-value compared to a home in a warmer climate. ENERGY STAR has a guide for the recommended R-value in your area.


Off-gassing frequently happens with spray foam insulation. This occurs when the chemicals from a solid or liquid turn into gas while they’re in the air. These gases can be harmful if they’re inhaled. When using spray foam insulation in your home, it’s recommended that you avoid being in the vicinity of the material for a period of time after installation.

Volatile Organic Compounds (VOC)

Volatile organic compounds (VOC) are both gases and odors that get omitted from insulation. The higher the VOC level, the more dangerous it is for a person to inhale it into their lungs. When searching for insulation, make sure you find something that has a low level of VOCs.

Drawbacks Of Fiberglass Insulation

Fiberglass is the most common type of insulation found in homes today. It’s made from tiny glass fibers, so fiberglass insulation can irritate a person’s skin and lungs. Because of that, it’s important to always wear protective clothing, gloves and a mask when working with fiberglass. While fiberglass insulation may be cheaper than some of the alternatives, there are other important downsides that should be considered.

  • Fiberglass insulation is a possible carcinogen. Fiberglass insulation packaging in the United States includes a warning that the product may have potential health risks. Some fiberglass insulations may contain formaldehyde, which is known to cause cancer. When installing, handling, or disturbing fiberglass insulation, it is important to wear a mask. A mask with a respirator or filter is recommended. Fiberglass particles floating in the air can be inhaled and could stick to your lungs, making it difficult to breathe over time. 
  • Fiberglass insulation can melt. Fiberglass insulation itself isn’t flammable, but for a long time, the paper backing used on rolls of insulation was. Today, most brands use nonflammable backing materials. But while fiberglass insulation might not be considered flammable, it does have the ability to melt in a fire. When this happens, it can cause an increase in the oxygen supply, which can accelerate a fire. 
  • Fiberglass is not environmentally friendly. Once installed in a home, fiberglass insulation helps to save energy consumption. Unfortunately, the production of fiberglass insulation can take up to three times as much energy as other insulation types. This is why people who are looking to make eco-friendly changes to their home stay away from fiberglass when possible. 
  • Reduced lifespan. Fiberglass insulation can be highly effective at reducing air transfer after installation. However, over time it starts to settle which reduces its R-value (more on R-value below) and effectiveness. 

How To Dispose Of Fiberglass Insulation

While you’re looking for insulation alternatives, you’ll want to think about the disposal of your current insulation. Fiberglass can be removed safely but it will need to be disposed of properly. Every community has guidelines for disposal or recycling of waste. Contact your local waste provider to discuss your options for proper disposal or recycling of your old insulation.

If you live in an older home and you’re not sure of the age or the type of insulation material you’re removing, it’s best to consult a professional. Old fiberglass insulation may contain vermiculite that could have asbestos fibers. Handling asbestos-containing materials puts the individual and the public at risk of developing asbestos-related illness and disease, so handle all insulation with care.

Alternatives To Fiberglass Insulation

Fiberglass is readily available and it’s easy on the wallet. But for those who want to stay away from fiberglass insulation in their homes, there are several non-fiberglass alternatives you can choose from. While these alternatives aren’t considered cheap, they are better for the environment, your home and your health.

Cellulose Insulation

  • Ideally used for: Cellulose insulation is great for anyone looking to use insulation made with recycled materials that are both fire and pest retardant.
  • Cost: $1.20 per square foot
  • R-value range: Between R-3.2 and R-3.8 per inch
  • Pros: The biggest benefit to using cellulose insulation is that it’s made from 75% – 85% recycled newspaper. This makes it extremely environmentally friendly compared to other insulation materials. It’s treated with boric acid, which helps repel insects and rodents. Cellulose insulation has an average VOC rating of 101 µg/m3 which is significantly lower than what most consider to be “low VOC.”
  • Cons: Installing cellulose insulation isn’t a DIY-friendly project. Because it’s blown, it can create a substantial amount of dust and it’s better to have it professionally installed. Cellulose insulation isn’t recommended for humid environments because it can retain moisture more easily than other types of insulation. This can increase the chances of mold.

Soy Insulation

  • Ideally used for: Soy insulation is a great option when you’re looking for something that contains no formaldehyde and will not off-gas any chemical byproducts.
  • Cost: Open cell soy insulation costs $0.44 – $0.65 per foot. Closed-cell soy insulation costs $0.70 – $1.00 per foot
  • R-value range: Open cell has an R-value of 3.6 per inch. Closed cell has an R-value of 6.5 per inch.
  • Pros: The biggest advantage to soy insulation is that it doesn’t give off any off-gases, which means it’s much healthier. It also does a great job of repelling rodents from the home. Because it’s a spray foam insulation, it will expand in size, filling hard-to-insulate areas, leading to a more energy-efficient home.
  • Cons: There’s a high upfront cost to install soy insulation. However, over time, the energy savings will begin the make up for the initial expense.

Spray Foam Insulation

  • Ideally used for: Spray foam is a great choice if you’re looking for insulation alternatives and want optimal energy efficiency in your home.
  • Cost: Spray foam insulation is available in two forms, open cell and closed cell. Open-cell spray foam costs $0.44 – $0.65 per foot. Closed-cell spray foam costs $1 – $1.50 per foot.
  • R-value range: Open cell spray foam has an R-value around 3.7 per inch and closed-cell can reach up to 6.5 per inch.
  • Pros: Spray foam insulation is great at filling all the little cracks and crevices. Once it’s sprayed into walls, it will expand, trapping moisture and air out. It’s also great at reducing noise transfer from the exterior of a home. Plus, as long as there are no moisture leaks, it will last much longer than other types of insulation.
  • Cons: Spray foam insulation can produce off-gases that can last anywhere from 24 – 72 hours after installation. Professional installation is recommended so it’s not ideal for the DIYer. Spray foam can also have a greater upfront cost compared to fiberglass insulation.

Natural Fiber Batts

  • Ideally used for: Using natural fiber batt insulation is ideal for anyone looking to create a green home.
  • Cost: The cost of different natural materials can vary but cotton batt insulation typically costs around $1.20 – $1.50 per square foot
  • R-value range: R-3.6 per inch
  • Pros: Different types of natural fiber batt insulation have very high longevity. For example, cotton can last up to 100 years without breaking down and becoming ineffective. Natural fiber insulation is also one of the most eco-friendly types of insulation. Cork even has a negative carbon footprint.
  • Cons: Most natural fiber insulation is quite a bit more expensive than fiberglass. It also has a slightly lower R-value. If natural fiber insulation is left untreated, it has a tendency to attract moths and other insects. However, most manufacturers today will treat the insulation with an eco-friendly solution.

The Bottom Line

While fiberglass insulation can be found in a lot of homes today, that trend is changing. Non-fiberglass insulation is growing in popularity because it’s safer for the environment and healthier for homes. If you’re thinking about insulating your home, be sure to discuss your disposal options with your local waste provider. If you’re unsure of the type of insulation you currently have, call a professional for their opinion. It’s always better to be safe than sorry.

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Carla Ayers

Carla is Section Editor for Rocket Homes and is a Realtor® with a background in commercial and residential property management, leasing and arts management. She has a Bachelors in Arts Marketing and Masters in Integrated Marketing & Communications from Eastern Michigan University.