Is aerolite flammable? (A 5-point guide)

This article will answer the following question: “Is aerolite flammable?”. We’re going to talk about the glass wool ceiling insulation from the Aerolite® brand, named Soft Touch.

Is aerolite flammable?

No. Aerolite insulation can’t catch fire. It’s mainly made of glass wool, which is not combustible or flammable. Aerolite is essentially an inorganic material that wouldn’t generate flames, gases, vapors, and fumes if tossed into a fire.

What is Aerolite?

Aerolite is a glass wool thermal and acoustic insulator that is bonded with an inert, thermosetting resin. The strong, resilient, flexible blankets are supplied in compression-packed rolls. To be installed, they must be cut.

By using Aerolite insulation is possible to reduce the energy required to keep a home or facility cold in the summer, and warm in the winter.

The product has fire, acoustic, and thermal properties that make it a suitable insulation material for many purposes.

Unlike other cellulose-based insulators, Aerolite can’t absorb moisture, so it will not breed fungi, mold, and bacteria.

How does Aerolite work?

There are many kinds of insulation products. Home insulation can be purchased in blankets, in batts, and materials that can be poured in a place, normally using special equipment.

Most insulations in buildings serve thermal purposes, but there’s also acoustic insulation, fire insulation, and impact insulation. Some materials serve more than one finality.

Nowadays, many thermal insulations also contains fire-retardant materials, which lower flames spreading if the material eventually catches fire.

Since aerolite uses glass wool as an insulating agent. The wool’s physical properties allow for maintaining the air within, which acts as a great thermal insulator.

Also, the air can’t migrate among the wool structure very well, so the gas exchange (and consequently heat exchange) won’t take place very well.

A good insulator is a material that covers the greatest area possible where heat exchange can happen between the inside and out. This effect is possible by using materials that prevent the heat flux, which is normally achieved by mixing air in the insulator.

The R-value

The R-value is an attribute that helps measuring how well a layer of insulation can resist thermal conduction, to figure out how thermal resistant it is.

The higher the R-value, the better the insulating properties a material has. It can be calculated through the following expression:

Rvalue= Temperature AreaFlow rate


  • “Temperature” is the difference in the temperature between the two sides of the barrier (in Kelvin scale);
  • “Area” is the exposed surface area of the barrier (in square meters);
  • And the “Flow rate” is the heat flow rate that goes through the layer (in Watts).

What is important in this equation is to understand how the R-value can be higher (which means, better or more suitable for heat insulation).

The more the temperature differs (let’s say, inside and outside a home), the more the heat is inclined to flow to achieve thermal equality. This means that more heat will pass through the insulation. But this depends overall on how the temperature is outside.

The area also can’t change, since it depends on the size of what’s been insulated.

The flow rate, although, is something that depends on the insulation material, how it’s assembled, and how the heat is dispersed on other attached materials (e.g other composites, or walls, roofs, etc.).

How does heat flux happen?

Heat is one form of energy. It has its own way to flow and/or dissipate. Generally, heat always goes from the hottest region to the coldest, but this is only valid when we think about heat itself.

Heat always requires a means to travel in. The closer and more combined molecules are to one another, the easier heat finds its way through, jumping from one atom to the other.

The air, although, is made of gases. Gas molecules take some time to pass the heat energy to each other because they can hardly touch each other. 

Some insulation materials are filled with trapped air, so even when the heat gets through it, the air molecules struggle to pass the energy forward. Air is a good kind of insulation in some conditions.

As we saw from the equation, the temperature difference is not enough for something to get colder or hotter, heat flow is also required. This is why we feel colder when the wind touches us, even though the temperature is the same with or without the wind.

How does Aerolite regulate the temperature?

Since it’s a great thermal insulator, Aerolite works by preventing heat that comes from the outside to pass through the mantle during the summer. In the winter, it helps maintain the heat that’s already inside the place, preventing it from leaving.

Combustible or flammable?

To be considered flammable a compound must have the ability to ignite easily and burn quickly, under normal conditions.

Combustible, although, is simply something that can catch fire.

These are general definitions. To correctly assess the information about how flammable a substance is, much more knowledge and research are required upon firing scenarios. 

Most of the Aerolite formula is made of glass wool, which is neither flammable nor combustible. Glass can’t catch fire because there’s no organic matter there to be burned.

Aerolite properties

Fire properties 

As we said, aerolite insulation itself can’t burn.

But even if it’s tossed into the fire, no smoke or other toxic fumes are expected to arise from it. This is because aerolite is not combustible, and thermal decomposition can’t happen easily in glasses.

According to the SANS 10177-5, a fire testing protocol in force in South Africa, Aerolite is considered not flammable and noncombustible.

According to a South African fire performance classification of thermal insulated building envelope systems, Aerolite has won the best fire classification (A1). This means that the product not only can’t burn but neither smoldering can happen.

Thermal properties

Aerolite can reduce heat loss and gain thanks to its inherent thermal insulation properties. 

The product has an R-value up to 3,38, higher than loose cellulose, fiberglass, and rock wool.

Specific properties

ThicknessR-ValueRoll LenghtRoll WidthDensity

You can check more specific data in the material’s Safety Data Sheet, available in this link.

Can Aerolite burn?

Aerolite is considered non-combustible.

No flames are expected to arise from the insulation, even if direct flames are applied. This is because the main ingredient in aerolite is glass, which can’t burn.

What is glass?

Glass is made from silica, which is silicon dioxide, also known as quartz. It is also the primal constituent of sand.

Glass is a transparent amorphous solid (it’s not crystalline, unlike most inorganic compounds).

Glasses can’t burn. They can be heated until reaching a red incandescent color, but no flames would arise from them. Since glass is made from a form of silicon that’s already oxidized, it can’t react again with air’s oxygen to burn.

Besides, fire only appears if the combustion reaction liberates energy, which normally only happens with organic compounds such as hydrocarbons, carbohydrates, alcohols, and other forms of fuel.

But what is fire?

Fire is what we see as the result of a combustion reaction. Combustion is just a specific form of oxidation. 

Not all oxidations are burnings, but all combustions are oxidations.

Fire takes place once oxygen reacts chemically with a source of fuel, and liberates energy that was trapped between the chemical bondings of fuel. Normally, this source is an organic compound. 

The heat of a combustion reaction breaks down the fuel molecules. The smaller molecules can then react more easily with oxygen, and liberate the energy within the fuel molecules.

This is the main reason why combustions are so intimately related to heat. The heat makes fuel molecules available to be burned.

In fuels, the carbon (C) was bonded with other carbons and hydrogens (H), but it is an opportunist that only cares about its stability, so he abandons hydrogen and marries oxygen forever (or until he finds an even better partner).

Most carbon bonds with two atoms of oxygen (O). This is the carbon dioxide molecule (CO2). Some eventually bond with only one oxygen, and those we name carbon monoxide, I highly toxic compound that will kill us certainly if we inhale enough of it.

But hydrogen, which is not dumb, also goes straight to other oxygen molecules. From this bonding, water (H2O) is the result.

Because carbon dioxide and water are very simple and stable molecules, they don’t react with oxygen again, so it’s impossible that the reaction turns the other way around spontaneously. 

Although, this is exactly what plants do. They simply take carbon dioxide, water (and other minor compounds) from the atmosphere, and craft sugars that will have many functions for the plant. 

Does Aerolite hold water like paper insulation?

No. Aerolite’s composition is fluffy and soft, but it’s nothing like paper insulation. Aerolite is essentially made of glass, which can’t hold moisture.

If water is applied to Aerolite it’s going to pass through.

How does aerolite insulation save money on energy?

According to the manufacturer, it’s possible to start saving money after the first month of using Aerolite. This is because the insulation is capable of reducing the energy required to keep a place warmer during the winter and colder in the summer.


Aerolite is not combustible and non-flammable. Also, even if something catches fire close to it, the Aerolite material itself wouldn’t burn, nor would generate toxic vapors, fumes, or smoke, as happens with other insulation materials.

Frequently Asked Questions (FAQS): Is aerolite flammable?

Is aerolite legit?

Aerolite insulations are among the most tested insulation productsacorss the world. It’s manufactured by a company that’s known worldwide.

Is pink aerolite dangerous?

There are a few considerations about skin irritation when in contact with pink aerolite insulations, but they are mild and only possible during the installation.

Aerolite doesn’t present any acute toxicity for humans and the enviroment. Also, even if tossed in the fire, pink aerolite wouldn’t generate much harmful fumes.

Can you touch pink insulation?

Touching the material without gloves may result in a sharp stinging, burning and itching sensation.


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