I was contacted by a homeowner about installing insulation in their house. I learned that a few days back, a house in their neighborhood caught fire, and the reason for the rapid spread of the fire was insulation. My worried client asked me, “Is Fiberglass Insulation Flammable?” because I recommend that insulation quite often.
According to the National Fire Protection Association (NFPA), fires caused $15.9 billion in property damages in 2022. These stats are enough to make us double-check our choices because safety should always be a priority.
So, is fiberglass insulation flammable? No, Fiberglass insulation is not flammable. It is specially made to resist fire and provide protection against potential fire hazards.
It is a common myth that fiberglass insulation is highly flammable.
It is one of the best choices for house insulation for many different reasons, and here in this article, I will tell you all about it.
What is Fiberglass Insulation and How does it work?
Fiberglass insulation is made from tiny glass fibers and is highly recommended by insulation experts. It will provide thermal protection to your house and reduce the risk of fire spreading all around.
It also helps in regulating the house temperature as it contains air pockets that trap air. It is like a cozy sweater for your house.
It is commonly used in walls, attics, and ceilings.
What Is Fiberglass Made Of?
The materials that are used to make fiberglass insulation are chosen with careful inspection to make it fire-resistant. It is primarily made from:
- Recycled Glass (40-60%): Melted down and spun into fibers.
- Sand and Silica: It is a main ingredient and a more eco-friendly option.
- Binders: They help hold the fibers together.
- Other minerals: Limestone and boron add to durability
The manufacturing process starts by melting glass to create thin strands. Next, these strands are grouped to make fiberglass. A binder is added to hold the fibers in place and enhance their strength.
Fire Resistance of Fiberglass Insulation
Fiberglass insulation is naturally non-flammable because it has a glass composition. Glass has a high melting point of around 1,500°F (815°C), which makes it resistant to fire.
Fiberglass insulation meets ASTM E84 standards, ensuring minimal contribution to flame spread. Compared to other insulation types, it also produces little smoke.
However, some of the materials used in fiberglass insulation, like kraft paper, are flammable. That’s why fire codes require covering these materials with drywall or other non-combustible barriers.
Testing Standards and Regulations
The American Society for Testing and Materials (ASTM) sets the standard for fire tests of building construction and materials Fiberglass insulation undergoes strict testing to meet fire safety standards.
- ASTM E84: It evaluates flame spread and smoke development.
- UL Classifications: It certifies the fire resistance of materials in different scenarios.
These standards ensure fiberglass insulation complies with building codes and safety regulations. Always check for certifications when purchasing.
Comparative Flammability
| Insulation Type | Fire Resistance | Standards Met | Key Features |
| Fiberglass Insulation | Non-combustible core; resists temperatures up to 1,500°F (815°C) | ASTM E84, UL 723 | Low smoke production, does not ignite; backing may vary |
| Foam Board Insulation | Flammable without fire retardants; melts under heat | ASTM E84, UL 94 (when treated) | Requires chemical fire retardants to meet safety codes |
| Cellulose Insulation | Treated with fire retardants; slows but doesn’t stop ignition | ASTM C739, UL Classified | Made from recycled paper; it depends on chemical treatment for fire resistance |
| Mineral Wool Insulation | Highly fire-resistant; withstands up to 2,000°F (1,093°C) | ASTM E136, UL 723 | Non-combustible; excellent fire barrier properties |
| Spray Foam Insulation | Combustible unless coated with a fire-resistant barrier | ASTM E84, UL 181 | Requires a thermal barrier to reduce fire risks |
Is fiberglass insulation flammable? You can see how fiberglass insulation performs comparably well against other insulation types.
Its glass-based composition offers natural fire resistance, while other types rely heavily on treatments or barriers to meet fire safety standards.
Also Read: Cellulose Vs Fiberglass Insulation
Factors Affecting the Flammability of Fiberglass Insulation
Although fiberglass itself doesn’t catch fire, several factors could impact its fire safety:
- Backing Materials: If the fiberglass insulation has paper and foil backing, it can be flammable.
- Installation Errors: During installation, gaps or improper coverage reduce effectiveness.
- External Elements: Dirt, dust, or contact with other flammable materials could pose a risk.
The materials used in the making of fiberglass insulation do not pose any risk on their own, but these small things are often overlooked, like backing materials and installation issues, which can be risky.
When it comes to home safety, it is always better to ask experts like ISID when it comes to insulating your house in Denver.
Safety Precautions and Recommendations
To enhance fire safety in your home, consider these best practices:
- Select backing carefully. Go for non-flammable or foil-faced insulation.
- Use drywall or fire-rated boards to shield insulation.
- Make sure to do weekly inspections. Check for gaps, wear, or other vulnerabilities.
- Keep insulation free from debris or flammable materials.
- Hire professionals because, when it comes to home safety, it is always better to ask experts like ISID when it comes to insulating your house in Denver.
People Also Ask
Is Fiberglass Insulation a Fire Risk?
Fiberglass insulation is not a fire risk. It has a non-combustible core and resists temperatures up to 1,500°F (815°C), making it a safe choice for homes.
Is Fiberglass Highly Flammable?
No, fiberglass is not highly flammable. Its glass-based composition naturally resists burning, though backing materials like kraft paper can ignite if not properly covered.
Which Insulation is Fireproof?
While no insulation is completely fireproof, mineral wool insulation is highly fire-resistant, withstanding temperatures up to 2,000°F (1,093°C), making it ideal for extreme fire safety needs.
How Much Heat Can Fiberglass Insulation Withstand?
Fiberglass insulation can resist heat up to approximately 1,500°F (815°C), thanks to its glass composition, which has a high melting point.
What Makes Fiberglass Insulation Safe in Fires?
Fiberglass insulation’s non-flammable glass fibers and low smoke production make it safe during fires. Following proper installation and using non-combustible backing materials enhances its safety further.
Is fiber insulation flammable? It is clear that fiberglass insulation is fire-resistant and a perfect choice for your house in Denver, where fire safety is a concern. Given that there are no external dangers, fiberglass insulation will offer an added layer of protection while giving all the benefits.
