Is Fiberglass Insulation Fireproof

There are many insulation options in the market.  Designed and developed to accommodate specific needs in each part of the home or building construction, these insulation materials, mostly, are created with fire-retardant chemicals.

“Fire retardant” is a common term used in the insulation business.  For many it means that the insulation products can withstand tremendous fire temperatures without breaking a flame.  This misconception has given many homeowners the comfort and security to even bypass safety measures.

What does “fire retardant” mean?

The term “fire retardant” means that it will ignite, there is no question about it.  However, the time lapse that passes from being exposed to fire and catching fire makes the whole difference.  Insulation material without a fire-retardant coating will catch fire 3x faster than those that have the fire-retardant coatings.

There are many chemicals that are customary to use in insulation products manufacturing as fire-retardant solutions for insulation materials.  One of these common chemicals is Ammonium sulfate, this chemical will increase the combustion temperature for the material in which it has been applied.

This means that, for instance (DISCLAIMER: THIS IS JUST AN EXAMPLE TO MAKE A POINT), if a material such as wool, it will ignite after 5 seconds of being exposed to fire, when wool has been submersed in ammonium sulfate, then it will withstand the exposure to fire for about 10 seconds, that is double the time.

In addition, it decreases the maximum weight-loss rates as the material as it burns. Increases the production of residue or char.  This means that the material in which the ammonium sulfate is applied to, will have a lower tendency to become “volatile” in terms of small fire specs that are often carried out of the major fire to parts that haven’t been burned yet.

Despite its benefits, there is a problem.  When the ammonium sulfate decomposes (through moisture) or becomes wet, it produces sulfuric acid; this byproduct is highly corrosive to metals and dangerous for humans and any residents of the home.

While it is a very handy and effective chemical fire-retardant solution, its characteristic to change to sulfuric acid makes most installers prefer cellulose chemically treated with boric acid and borax.

Still, there is a benefit and the insulation industry has come up with corrosion inhibitors being added to the chemicals used to moisten the cellulose-faced insulation products.

If you want to use insulation materials that have been prepared with this fire-retardant, it is important to make sure that there is no source or potential source for water nearby the insulation material to prevent it from getting wet. If you are insulating your ceiling, you will also need to ensure that there are no water leaks or vapor leakage from the rest of the home. 

Kraft paper backed insulation fire hazard

 Among the list of many problems that a homeowner or contractor has to deal with when replacing or installing insulation in a building is the risk of a fire hazard. This is something none of us want to experience in our homes.

Upon installation of the new insulation or replacement of the old one, make sure that services installations such as gas, electricity and water have been properly isolated and their installations are in pristine condition. If they are not, then you will need to change or correct them until they are. 

One thing that we need to care for is the insulation that is installed or to be installed in our homes.   Insulation can be a very positive thing, but this positivity can also turn to become something negative as it explodes and combusts in fire.

Danger in all places

The right insulation applied the right way will enhance your home’s indoor weather and will save you thousands in energy bills.  However, this same insulation can burn and release toxins and poisonous gases into the very air that, in a fire, you will struggle to breathe.

When a fire starts, the same insulation that prevents warm air to leave your home will prevent -to an extent- fire from rapidly spreading into other areas of the house, but it will make the temperature of the room higher and that, in extinguishing a fire, can become troublesome if the fire department isn’t called on time.

After a while of being exposed to a fire source, all insulation will start to cave in and catch fire.  In those cases where the insulation does not combust, it is certain it will melt and it can burn and cause other surfaces and materials to catch fire.

How does it catch fire?

Insulation materials can combust as part of a building burning or as the chief source of fire. If the fire starts elsewhere in the home and as the fire progresses, it combusts the insulation materials, then they burn as part of the burning building. If they ignite because of a short circuit in their vicinity, then they will burn as the chief source of fire. 

Short circuits are just an example, there is no way to single out a source for a fire.  It can be a match, a cigarette- or any other source.  It is important to know that the electrical installation of your home can also be the source of the fire. 

When the installation of the insulation is poorly done, it puts at risk the house since most likely, installations such as water, gas, electricity and even the weatherproofing of the roof and outside of the house are equally shady. In one such example, the electrical circuits are suffocated with the insulation material. 

Such action will probably overheat the electrical cords and, in time, it can lead to a short-circuit and the consequential fire.

In addition, if the insulation material is covering other installations without the proper consideration, such as the heat-producing devices can affect their performance and consequently force you to spend more money to have them working properly.  This is without considering that any appliance will overwork and overheat.

Toxicity

Undoubtedly, all insulation materials burn.  They are not fireproofed as there are few materials that can withstand long and heavy exposure to fire.  Mostly, any construction- or home-related materials will burn even if they do not so immediately.

However, since the moment the insulation products are exposed to fire, their chemical structure changes and there will be a release of toxic gases and smoke.  The amount of gasses and smoke released will vary and become more intense the longer the insulation materials are exposed to the fire.

In the same manner, if a person is exposed to these toxic releases, he or she will begin to feel sick and dizzy. If the exposure is prolonged, it can be life-threatening.  While kraft insulation has paper backing, the paper has been treated and it will also release toxic smoke and gasses like any other form of insulation.

As the fire consumes the insulation material, the smoke will get thicker and it can cause problems for the inhabitants of the home when they try to get out of harm’s way.

It is always a superb idea to be additionally careful how you install insulation materials that have a paper backing of any kind.  Especially if these papers have oily substances added for functionality and/or efficiency.

Sometimes insulation materials that have paper backing have additional materials such as asbestos.  While these might be banned or prohibited in your area, they can be extremely dangerous for your health if they are exposed to fire.

Something else to know about.

Despite the evidently logical reaction of insulation to fire, there are those who firmly believe that insulation is fireproofed, and the fact that it is stated as fire-retardant means that it will neither succumb to the exposition to fire.

Consider typical insulations; these are made of wood, paper, cork, and cotton as their primary materials.  These materials are known as “cellulose insulation” as they are related to this by their source, origin or the fact that they can be considered byproducts.

The proposal of being retardant lies because in most cases, cellulose-derived and kraft paper-faced insulation are often covered in one or more layers of fire-retardant chemicals.  These chemicals are referred to as “Thermal barriers”.  Their sole purpose is to actually ensure that the ignition of the materials as they are exposed to fire for a long period of time is delayed.

The concept in this is that by delaying the ignition of the materials as they are exposed to fire, it will give time for either the fire department or the homeowner to arrive to the ignited area with a fire extinguisher or any other fire-battling tool that will prevent the insulation from getting caught on fire and causing the evident damages.

While these thermal barriers are required by the Consumer Product Safety Commission, each fire situation is unique and it can’t be bundled with any other as part of a generic situation.  It is important to consider that while the insulation passes the CPSC requirements, it may react differently than expected when given the condition for a particular fire.