Fiberglass, Is It Fire Resistant?

Fiberglass is one of the most popular insulating materials used in house construction, today. It’s a very low-cost material and it’s easy to stuff into spaces between interior and exterior walls and mute the radiation of heat from inside your home to the outside world. It is also used in boats, aircraft, windows, and roofing. However, is it possible that this insulating material might be able to catch fire and put your home at risk?

Fiberglass is not flammable, as it was designed to be fire-resistant. However, that doesn’t mean that fiberglass won’t melt. Fiberglass is rated to withstand temperatures up to 1000 degrees Fahrenheit (540 Celsius) before it will melt.

In reality, as the name suggests, fiberglass is made out of glass and it consists of superfine filaments (or “fibers” if you will). The insulating material is made up of filaments scattered at random on top of each other, but it is possible to weave these fibers together to create other more unusual applications of fiberglass.

Depending on how the fiberglass will be used then there may be other materials added to the mix to change the strength and durability of the end product.

One popular example of this is fiberglass resin which can be painted over a surface to reinforce it but it may also be true of a fiberglass mat or sheet (often used in the construction of boat hulls or surfboards).

Fiberglass is often confused by people with carbon fiber, but the two materials are not in the remotest bit chemically similar.

Does It Catch Fire?

In theory, fiberglass can melt (doesn’t really burn), but only at very high temperatures (above an estimated 1000 degrees Fahrenheit).

Melting glass and plastic is not a nice thing and it poses severe health risks if it splashes on you. It can result in far worse burns than a flame could bring and may adhere to the skin requiring medical assistance to remove.

So, if the fiberglass near you is melting, move away, and either use a fire extinguisher on it or call for help.

If you are ever in doubt of your ability to tackle a blaze, it’s always best to call the professionals, never take an unnecessary risk yourself.

Is It Fire Resistant?

Fiberglass, especially in the form of insulation, was designed to be fire-resistant and does not catch fire easily, but it can melt.

Take a look at this video testing the fire resistance of fiberglass and other insulating materials:

However, fiberglass can melt (though only at very high temperatures) and you wouldn’t want to coat many things in fiberglass to try and prevent them from burning.

What About Fiberglass Insulation?

Fiberglass insulation is not flammable. It will not melt until temperatures are over 1,000 degrees Fahrenheit (540 Celsius), and it will not readily burn or catch fire at low temperatures.