Is fiberglass insulation burnable?

Author: Astrid Sauer MD  |  Last update: Wednesday, October 1, 2025

Fiberglass insulation is non-flammable and will not burn, but it can melt at high temperatures above 1,000 degrees Fahrenheit. The binding material may char or release smoke, but the fibers themselves are fire-resistant.

Is fiberglass insulation fireproof?

While fiberglass insulation is not entirely fireproof, it is designed to be fire-resistant and slow down the spread of flames.

Can fiberglass withstand fire?

Pure fiberglass can be considered fireproof because it doesn't burn or contribute fuel to a fire. However, when combined with certain resins or binders, which may be used in some fiberglass products, the overall fire resistance can be compromised.

Will fiberglass insulation melt?

It can also withstand temperatures up to 1,000 degrees Fahrenheit. However, fiberglass can melt if exposed to high temperatures for a prolonged time and may contribute fuel to a fire. It's important to install fiberglass insulation according to building codes and manufacturer instructions.

What is the biggest problem with fiberglass insulation?

Air Leakage

Fiberglass insulation is less dense than other types of insulation and does not create an airtight seal, which means air can travel freely through the insulation. This is called air leakage and it's one of the most common sources of energy loss in a house.

Mineral wool vs fiberglass insulation | everything you need to know

How bad is fiberglass insulation for you?

Exposure to fiberglass can cause irritation in the eyes, nose, or throat. It may also cause itching and irritation when the fibers get stuck in the skin.

Is there anything better than fiberglass insulation?

In many ways, mineral wool is a superior insulation product. It has a higher R-value per inch compared to fiberglass, about a 22-37% higher R-value. It contains 70% recycled material, making it a greener product than fiberglass at 20-30% recycled material..

Should I remove old fiberglass insulation?

Another good reason to remove that old, ineffective insulation in your home has everything to do with keeping your family healthy. Fibreglass and cellulose are known to retain allergens. These issues can lead to health problems, which is something you want to avoid.

At what temperature does fiberglass melt?

Generally, fiberglass has a melting point that ranges from around 1,000 to 1,400 degrees Celsius (1,832 to 2,552 degrees Fahrenheit). This high-temperature tolerance makes fiberglass insulation a practical choice for applications where heat resistance is crucial.

Is fiberglass insulation ruined if it gets wet?

Every type of insulation will react differently when it gets wet. Fiberglass insulation will lose its effectiveness as air is displaced by water, causing it to conduct heat instead of insulating your home. Cellulose will begin degrade if it's not dried quickly, and it can start to grow mold.

What type of insulation is fireproof?

To sum up, choosing mineral wool, cellular glass, or closed-cell insulation that is incombustible and nonabsorbent provides the highest level of fire safety. Such types of insulation won't add to the spread of fire, nor release toxic smoke and fumes.

How to get rid of fiberglass insulation?

After removing the staples, simply roll out and fold the fiberglass insulation individually. It's best to start from the farthest corner of the room. Discard them in large garbage bags. Talk to your local waste management department to know where you can take them for proper disposal.

How flammable is Fibreglass?

Fibreglass. Fibreglass insulation is also non-combustible, meaning it will not contribute to a fire. However, it has a lower melting point, at around 540°c, meaning it could melt during an intense house fire, allowing flames to spread to other flammable materials within the construction.

How heat resistant is fiberglass insulation?

Due to its composite, inorganic nature, fiberglass can withstand some of the most extreme temps while still maintaining its form. Fiberglass can retain 50% of its strength at 700° Fahrenheit (371° Celsius) and 25% of its strength at 1000° Fahrenheit (538° Celsius), making it ideal for industrial use.

Does insulation need to be fire rated?

By meeting stringent fire safety regulations and standards, fire-rated insulation enhances the overall fire resistance of the structure, protecting occupants and property alike. Bottom line: Choosing the right fire-rated insulation class for your next project is absolutely crucial.

Can I use fiberglass insulation for fire blocking?

Batts or blankets of mineral or glass fiber or other approved nonrigid materials shall be allowed as fireblocking in walls constructed using parallel rows of studs or staggered studs.

Does fiberglass insulation burn or melt?

Fiberglass insulation is non-flammable and will not burn, but it can melt at high temperatures above 1,000 degrees Fahrenheit. The binding material may char or release smoke, but the fibers themselves are fire-resistant.

How fireproof is fiberglass?

Fiberglass can withstand high temperatures, with its average melting point being 540oC.. Another crucial property of fiberglass is its fire resistance. It will not catch fire and prevent fire from traveling through it, reducing the spread.

Is pink fiberglass insulation fireproof?

Safe Proven Ingredients. A safe home environment begins with the materials used to build it. Owens Corning® PINK Next Gen™ Fiberglas™ insulation is made with safe, proven ingredients that naturally resist fire and do not support mold growth, with no formaldehyde and no fire retardants added to the fiberglass.

How many years does fiberglass insulation last?

Common Lifespans of Different Attic Insulation

Natural materials will inevitably degrade faster than synthetics, and some high grade synthetic materials can last virtually indefinitely if well taken care of. Fiberglass Insulation--The actual lifespan of this commonly used attic insulation is from 80-100 years.

Why not to use fiberglass insulation?

Misused & Susceptible to Water

Often fiberglass insulation is misused when it's installed. An example of misuse is when it is installed in a basement ceiling. Fiberglass insulation is easy for air to move through and it loses a high percentage of its R-value when it gets water into it.

Can you throw away fiberglass insulation?

You cannot throw old insulation away because you need to dispose of it properly so you don't cause environmental harm. Fortunately, many waste management companies will relieve you of your old insulation and dispose of it safely. You may have to pay a processing and handling fee, but these are usually minimal.

Is spray foam really better than fiberglass insulation?

The higher the R-value number, the better the thermal protection against heat transfer from outside sources into your home/business environment (or vice versa). Spray foam has a higher R-value rating than fiberglass that makes it more effective at preventing heat transfer from inside or outside.

How can you tell if insulation is fiberglass?

Fiberglass fill is a loose-fill insulation that is white and fluffy and has a little shine. The insulation may produce a slight shine when exposed to bright light because fiberglass is a glass product. It is very soft, almost like cotton candy, and composed of very fine fibers.

What is the healthiest type of insulation?

There are other types of insulation, but these are the most common. The best non-toxic insulation is either mineral wool or foam insulation inserts.

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