Fiberglass vs. Rockwool Insulation – Which Is Best For Your Home?

Picking a type of insulation for your home is a tough yet very important decision. If your home or building is struggling to keep at a stable temperature in the summer or winter, it is time to think about improving your insulation.

There are many different types of materials used for insulation, but today we’ll look at the pros and cons of fiberglass vs. rockwool insulation. The right insulation ensures proper ventilation, fire and health safety, and cost efficiency.

What Is Fiberglass Insulation?

Before deciding between fiberglass vs. rockwool insulation, we must understand how each type of material works. Fiberglass is a popular material used for insulation in homes. Made from sand and recycled glass, fiberglass is what most people assume and think of when they hear the word insulation. The pink or yellow, cotton-candy look-alike material lines the inside of the walls and attic space.

Fiberglass has been used for over 80 years to keep homes and businesses cool in the summer and warm in the winter. Fiberglass is a popular choice because it is affordable, effective, and readily available. Using fiberglass insulation gives you immediate relief and results. Your air-conditioning units will not have to work as hard, which saves you a ton of money on your energy bills in the summertime! Using less energy also directly helps reduce your carbon footprint and lower your impact on the environment.

How Does Fiberglass Insulation Work?

When fiberglass insulation is installed in your residential or commercial building, it provides a natural sound barrier that reduces transmission. It easily fits between the framing of the building, so you do not have to worry about building in extra space for insulation to fit. The final installation of fiberglass fits nicely and easily into the already-built structure of your home or business.

Fiberglass is also a non-flammable insulator, offering extra comfort and peace of mind when choosing it as your insulation material.  It has resistance to high temperatures, humidity, and chemical and biological effects, while also having a relatively low density. Fiberglass has many unique properties that make it a great option for your choice of insulation.

FAQs of Fiberglass Insulation

Q: What is fiberglass made out of?

A: Fiberglass is made of sand and recycled glass.

Q: Is fiberglass safe to touch?

A: Fiberglass insulation should be installed and handled by professionals. While it is safe to have fiberglass in your home, it is best not to touch this material with bare hands or inhale it in any way. Calling the professionals at Ideal Insulation is a great option to ensure proper installation and safe care of the material.

Q: How long does fiberglass insulation last?

A: Fiberglass is a wonderfully long-lasting and durable product. It can take up to 50 years to decompose and need reinstalling. Fiberglass is a great choice for insulation material because of its longevity.

Q: What causes fiberglass to give out?

A: While fiberglass is a durable material, it is not indestructible. Long exposure to high temperatures will reduce the strength of the fiberglass as a whole. It can lose nearly 50% of its strength after prolonged exposure to elevated temperatures.

Q: How many layers of fiberglass do I need?

A: In order to have ¼ inch of fiberglass insulation, you will need about eight layers of fiberglass.

What Is Rockwool Insulation & How Does It Work?

You know the basics of fiberglass insulation now, but it is necessary to understand the fundamentals of rockwool insulation. Rockwool insulation, as it says in its name, is made from rock and other raw materials. They are melted until formed into a wool-like texture, similar to fiberglass insulation, then flattened and formed into flat sheets. It is usually a gray or other neutral color depending on the specific rocks and raw materials in that batch.

Rockwool insulation has comparable qualities to fiberglass insulation. Like fiberglass insulation, rockwool provides an extra layer of sound protection. It helps to create a barrier within the walls to help soundproof the room, as well as keep the cool or warm air inside. Because of its flexibility being able to easily use the batts, sheets of flat, pre-cut insulation, and line the interior of the frames in the home, rockwool became a popular choice as the material for insulation. Rockwool is a thick material that helps to keep the cool air inside during the summer and the warm air inside during the winter. This reduces the amount of energy homeowners use on air conditioning and heat during the peak times of the year. Upgrading a home’s insulation is vital in keeping long-term costs lower while maintaining a comfortable temperature in the home year-round.

Caption: Man installing rockwool insulation from batts while wearing protective gear.

How Does Rockwool Insulation Work?

In the same way that fiberglass insulation is installed in your residential or commercial building, rockwool insulation is also installed throughout the building’s framing. Rockwool usually is sold in batts, which can be cut and adjusted to the perfect size of the framing in your home or business. Since it is nestled throughout the walls, it distributes the sound creating a natural sound barrier that reduces sound transmission through the building. Fiberglass vs. rockwool insulation both offer fire resistance. Rockwool is also a non-flammable insulator, helping to alleviate the worry of a potential fire spreading inside. Rockwool is one of the most popular insulation materials for areas with increased fire hazards. While fiberglass vs. rockwool insulation is a hard choice to make, there are so many commonalities that prove both as viable, good options.

FAQs of Rockwool Insulation

Q: What is rockwool made out of?

A: Rockwool is made of raw materials, like rocks, steel, and slag.

Q: Is rockwool safe to touch?

A: Unlike fiberglass insulation that can cause serious injuries if touched with bare skin or inhaled while installed, rockwool does not pose any threats to human health. We always recommend leaving insulation installation to the professionals at Ideal Insulation, rockwool will not cause harm.

Q: How long does rockwool insulation last?

A: Rockwool is an incredibly durable material with great longevity. Since it is made out of inorganic material, rockwool does not decompose and should last the full length of your residential or commercial building. Rockwool is a great choice for insulation material because of its long-lasting properties.

Q: What causes rockwool to give out?

A: As long as no physical damage occurs, such as removing pieces of the rockwool insulation, or serious flooding causes significant damage, rockwool insulation should remain intact and in use.

Q: How many layers of rockwool do I need?

A: It depends on the size of the batts that you purchase, but we always recommend double layering the rockwool insulation upon installing throughout the interior walls and ceiling of your home or commercial business.

Fiberglass vs. Rockwool – A Brief Comparison

Knowing the basics of fiberglass vs. rockwool insulation is important when deciding which material is the best for the needs of your residential or commercial building. Read through a side-by-side comparison of crucial factors when deciding which material you should choose!

Q: What is the price difference?

A: Fiberglass batts cost around $0.30 to $1.50 per square foot. However, it can also be installed using the blown technique for attic insulation. This method costs more as it required extra equipment, but fiberglass is the most affordable material when choosing the blown installation process. Rockwool batts are slightly more expensive than fiberglass batts, ranging between $0.62 to $2.10 per square foot.

Q: Is fiberglass or rockwool quicker to install?

A: Both are very easy and quick to install! Fiberglass and rockwool both come in batts, but fiberglass can be blown as well.

Q: Environmental Impact of Fiberglass vs. Rockwool Insulation

A: Fortunately, both fiberglass and rockwool are made of relatively eco-friendly materials. Fiberglass is made of recycled glass and sand, which is a renewable resource. Rockwool is made of raw materials such as rocks and minerals, which are abundant throughout the Earth. Both of these are great options for insulation when considering the environmental impact.

Q: Does Fiberglass vs. Rockwool insulation have a better R-value?

A: The R-value represents the heat resistance of insulation. The lower the R-value, the less heat the insulation can block. Fiberglass has an R-value between 2.2 – 2.7 per inch. Rockwool has an R-value between 3 – 3.3 per inch. Rockwool is the winner when looking strictly at the R-value, but of course, there are other factors that play into your decision of which insulation material you should use for your space.

Q: Is Fiberglass or Rockwool better for my attic space?

A: We really like both of these options for your attic space insulation. If you want it blown in, fiberglass is the best route. However, rockwool is the better option if you want batt installation.

Q: When should I use blown insulation?

A: Blown insulation can be the preferred method depending on your needs. If you have gaps and cracks throughout your home, need to insulate hard-to-reach places, are looking for a more environmentally friendly choice, or want an option that is less likely to settle over time, blown insulation is your best bet!

Q: Do I have to get rid of my old insulation before adding in new fiberglass or rockwool insulation?

A: The only reason you would need to remove existing insulation is to get rid of mold. If you have a flood or serious storm that damages your current or previous insulation and it grew mold, it is necessary to remove that before installing your new material. Whether you are choosing fiberglass vs. rockwool insulation, having a clean area, free of mold or mildew, to install the new material is essential. It is very important to address wet insulation immediately. It can cause serious problems in the future if left undiscovered and untreated.

Q: Which is the best for my space, fiberglass vs. rockwool insulation?

A: Here at Ideal Insulation Company, we offer free quotes based on your individual needs for your insulation. It is impossible to say which is best between fiberglass vs. rockwool insulation without understanding your insulation needs. Contact us now and tell us why you are looking to upgrade or replace your existing insulation or add insulation to a new construction property!

Call the Professionals to Help Decide Between Fiberglass vs. Rockwool Insulation

After reading through the positives and negatives for both fiberglass and rockwool insulation, it still becomes an individual decision. It is tricky when choosing between two effective types of insulation! Consider your location, budget, and time frame when picking a type of insulation for your residential or commercial property. It is always best to call the pros so that we can determine the best choice for you! Don’t hesitate to reach out for a free quote to insulate your building before the heat of the summer comes in strong!

Like this article?

Share on Facebook
Share on Twitter
Share on Linkdin
Share on Pinterest

Proud To Serve In These Cities:

Metro Atlanta

College Park
Druid Hills

Flowery Branch
Forest Park
Holly Springs
Johns Creek
Lithia Springs
Mountain Park

North Decatur
North Druid Hills
Powder Springs
Sandy Springs
Sugar Hill
Union City
Villa Rica

Contact Us