Does Fiberglass Conduct Electricity?

In this article, we will cover whether fiberglass conducts electricity or not.

Fiberglass is a very versatile material with many useful properties that make it a good alternative to traditional construction materials. But what about electrical conductivity, i.e., does it conduct electricity? Before explaining further, here’s the short answer:

Normally, fiberglass is a non-conductive material, i.e., it does not conduct electricity. This gives it an edge over alternative materials where electrical insulation is preferred over conductance. However, there is a way to make it electrically conductive, which makes it also useful in other situations where conductance is required.

In this article, we go through the electrical properties of fiberglass in detail and explain all you need to know.

What is Fiberglass?

Fiberglass, also called GRP (Glass-reinforced plastic), contains woven material embedded with glass fibers. These are bonded using a binding substance that makes the fiberglass a very strong form of plastic. When combined with resin, it is made even more durable. Fiberglass is also lightweight, flexible, and inexpensive.


Why Does Fiberglass’ Electrical Conductance Matter?

Whether fiberglass conducts electricity matters because fiberglass is used to replace traditional materials like aluminum and steel which are more widely known to conduct electricity. Its high strength, low weight, water resistance, and low thermal conductivity make it very versatile besides other useful properties. But how fiberglass compares in terms of electrical conductance can make a big difference in situations where electrical conductivity is important.

In some situations, a good conductor is required, and in others, a good insulator. Since fiberglass does not behave like metals, it offers a different combination of properties for the materials for which it is a suitable alternative. Let’s understand why it does not conduct electricity before seeing how it can be useful.


Why Does Fiberglass Not Conduct Electricity?

Like wood, which is another material for which fiberglass is used as an alternative, fiberglass does not conduct electricity because it is good at insulating against the flow of electricity.

The glass and resin from which fiberglass is made are poor conductors of electricity. Glass, for example, contains silica sand, limestone, and soda ash. Unlike metals, all these ingredients have high resistivity. Glass offers a resistance of around 1012Ωm [1], which is very high.

The materials from which fiberglass is made have a rigid structure and do not have free electrons. Consequently, fiberglass, which is a composite of them, also does not conduct electricity. In short, it is the lack of free electrons that makes fiberglass not conduct electricity.

Furthermore, fiberglass is permeable to air because it is porous, and it has high dielectric strength, which is the maximum electric field strength material can tolerate before it breaks down and starts conducting electricity. Both of these qualities make fiberglass a good insulator rather than a conductor of electricity.

Fiberglass does not normally conduct electricity because…
It is made from highly resistive materials.It has no free electrons.It is permeable to air (porous).It has high dielectric strength.


How is Fiberglasses Insulating Property Useful?

The fact that fiberglass does not conduct electricity and is a good insulator like wood makes it useful in many ways. It is especially useful in all those situations when we strictly need the material to resist or prevent the flow of electricity.

For example, fiberglass is used in making insulation tubes or cable sleeves for safely enclosing electrical wires and cables (see picture below). Fiberglass is also strong enough to make objects like ladders. They can be used by electricians who need to work in high places without the risk of the ladder conducting electricity, as can happen to an aluminum ladder.

fiberglass insulation tubes or cable sleeves
Fiberglass insulation tubes or cable sleeves
a fiberglass ladder
A fiberglass ladder

Another useful situation to use fiberglass is when you need to allow EM (electromagnetic) signals to enter your home easily to facilitate wireless communications.

Materials like aluminum, steel, and concrete inhibit EM waves because they are electrically (and magnetically) conductive. They distort or block wireless signals. In comparison, fiberglass is effectively transparent to EM waves, including cellular frequencies. Fiberglass thus provides some benefits over its alternatives, such as strength and durability, in certain situations without the drawback of distorting or blocking wireless signals.

This advantage of fiberglass over other materials makes it a good choice in the telecommunications sector. It is used, for example, to cover antennas, other telecommunications equipment, and cell tower screening.


Can Fiberglass Be Made to Conduct Electricity?

In certain situations, it can be useful to make fiberglass behave more like its metallic alternatives by making it conductive of electricity. For these situations, making fiberglass conduct electricity is possible. It is done by integrating a certain composite material into the fiberglass which is itself electrically conductive.

Usually, aluminum fibers are combined with fiberglass to give it this property. Another method could be to give the fiberglass a conductive coating if that is helpful for how it will be used. One example is aluminum-coated glass fiber cloth used in welding and preservation (see picture below).

aluminum coated glass fiber cloth
Aluminum-coated glass fiber cloth


Wrapping Up

We explained above in detail whether fiberglass conducts electricity or not.

Normally, it does not conduct electricity, and it is a good insulator because it is made from materials (glass and resin) that themselves have high resistance due to the lack of free electrons and other properties.

However, it can be made to conduct electricity if needed. In either case, whether it is designed to conduct electricity or not, it has several uses and may be a good alternative option over other materials.

Take a look at some of our related articles below.

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About Sam Orlovsky

b1d87d2ee85af3e51479df87928bdc88?s=90&d=mm&r=gCertifications: B.E.E.
Education: University Of Denver - Electric Engineering
Lives In: Denver Colorado

Electrical engineering is my passion, and I’ve been in the industry for over 20 years. This gives me a unique ability to give you expert home improvement and DIY recommendations. I’m not only an electrician, but I also like machinery and anything to do with carpentry. One of my career paths started as a general handyman, so I also have a lot of experience with home improvement I love to share.

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