Last updated: August 11, 2021

Welcome to our big glass wool test 2021. Here we present all the glass wool we have tested in detail. We have compiled detailed background information and added a summary of customer reviews on the internet. We would like to make your purchase decision easier and help you find the best glass wool for you. You will also find answers to frequently asked questions in our guide. If available, we also offer interesting test videos. Furthermore, you will also find some important information on this page that you should definitely pay attention to if you want to buy glass wool.




The most important facts

  • Glass wool is an insulating material made from mineral and synthetic substances. Glass wool can be used flexibly and in many ways to insulate roofs, walls and facades.
  • Glass wool has the particular advantages that it has a specific bulk density, requires little insulation thickness, is made of a particularly durable material, has high heat protection and is resistant to mould and vermin.
  • When insulating with glass wool, it is especially important to take precautions and work with safety equipment so that you are protected from health risks.

The Best Glass Wool: Our Picks

Guide: Questions to ask yourself before buying glass wool

What is glass wool?

Glass wool is one of the most popular insulation materials. It is a mineral that is made from mineral and synthetic substances. In most cases, waste glass is used for this purpose. Glass is melted with limestone or sand admixtures and spun into long threads. In this way, a fleece is created with the addition of binding agents.

Glass wool is a particularly durable material that is resistant to vermin and mould due to its mineral base. (Image source: Unsplash / Charles 🇵🇭)

In the following list, we have once again summarised the various properties of glass wool for you:

  • Specific bulk density
  • Low insulation thickness required
  • Durable material
  • Good heat protection
  • High fire protection due to the composition of the material
  • Resistant to mould
  • Resistant to vermin

No different product types can be identified for glass wool. Glass wool only differs minimally in various properties such as bulk density, thermal conductivity, water vapour diffusion resistance and heat capacity.

What can you use glass wool for?

Glass wool is used as an insulating material and is versatile and flexible. Glass wool is particularly popular for impact sound insulation in ceilings. The material also impresses with its particularly good thermal insulation properties.

Glass wool is also used for roof insulation, interior insulation and facades.

Basically, it can be said that glass wool is an insulating material that can be used universally for all kinds of insulation in the house. Insulation materials such as glass wool are also particularly popular for insulating heating and service water pipes as well as air conditioning and ventilation pipes.

What do you have to look out for when using glass wool?

When using insulation materials, regardless of whether they are older or newer materials, some precautions must be taken. Otherwise, health problems such as skin irritations may occur. Here you will find the most important points when working with insulation material such as glass wool:

  • Do not unpack insulation material until it is ready for direct use
  • Do not discard material
  • Do not use compressed air
  • Soak up residues and do not sweep up
  • Clean the workplace regularly
  • Put waste into suitable containers
  • Use suitable protective clothing and goggles
  • Rinse away construction dust with water
  • Do not touch insulation material with bare skin
  • Provide adequate ventilation at the workplace
Did you know that an additional air sealing system is important for an insulation layer? Without an airtight system, air can get into the insulation layer through leaking sockets and edge connections, causing moisture to accumulate. This can cause serious structural damage. With the help of an airtight system and seamlessly bonded vapour barrier foil, air should be prevented from getting in or out.

What alternatives are there to glass wool?

There are various alternatives to glass wool, which can score points due to their similarities. There are also other options, which are described in more detail in the following table.
Type Description
XPS Used as an alternative to glass wool and is produced synthetically. XPS has comparable properties to glass wool (insulation properties 0.038 per metre and Kelvin)
Hemp Hemp is an environmentally friendly alternative and has similar insulation properties to glass wool. (Insulation properties 0.039 Watt per metre and Kelvin) Hemp also scores points because it can be used as sound insulation. However, this insulation material has a lower fire protection class than glass wool.
Rock wool like glass wool, rock wool belongs to a type of mineral wool and is similar in processing. However, in stone wool, stones such as basalt, limestone, feldspar or dolomite are melted and recycled stone wool is also used. The differences between glass and rock wool are often very minimal. Compared to glass wool, rock wool is heavier and has a higher bulk density and is therefore less flexible.

Buying criteria: You can use these factors to compare and evaluate glass wool

In the following, we would like to show you which factors you can use to compare and evaluate glass wool. This will make it easier for you to decide whether a certain product with glass wool is suitable for you or not. In summary, these are:

  • Bulk density (kg/m3)
  • Thermal conductivity
  • Building material class

Bulk density (kg/m3)

The raw density has a great influence on the type of fastening (gluing, dowelling, etc.) of the insulation material. The weight also plays a role in stressed building areas such as roof trusses. The raw density also has an effect on the thermal insulation properties. Thus, low raw density reduces thermal conductivity. In comparison, insulating materials should have a bulk density of between 20 and 100 kg per m3. In the case of glass wool, the bulk density is between 15 and 150 kg per m3.

Thermal conductivity

Thermal conductivity is very important because it is a measure of how well a material insulates. It is important to remember that the lower the value, the better the material insulates. This key figure is also known as the lambda value and reveals how much heat penetrates through the insulating material to the outside.

A good heat storage and thermal conductivity of an insulating material is particularly important. This is because heat can be stored more easily and is also released again slowly, which can also be an advantage in summer.

The glass wool should have a thermal conductivity in W/(m*K) of 0.032-0.040. You can tell if your insulation material has good thermal conductivity if the value is below 0.03 W/(m*K).

Building material class

The building material class is used as a classification for fire protection. This subdivision is from A1 to F. For example, the designation building material class A1 stands for non-combustible, B2 for normally flammable and F for easily flammable. Glass wool should have a building material class such as A1, A2, B1 (DIN 4102-1) A1, A2-s1, d0.

Facts worth knowing about glass wool

How can you cut glass wool?

As mentioned before, there are a lot of things you have to consider when working with glass wool or other insulation materials, so it is also important to take some things into consideration when cutting glass wool. The following points summarise what you need to pay attention to:

  • Cutting glass wool outdoors
  • Use a solid surface for cutting glass wool
  • Use an old but sharp knife for cutting, preferably a bread knife or a special insulation knife
  • Use protective clothing during the work
  • Clean the workplace thoroughly afterwards and take a shower for safety's sake

https://www.youtube.com/watch?v=PkI0H0ese3I Before you start cutting, you should check whether you can buy your insulation material cut from the manufacturer.

How can I dispose of glass wool?

Glass wool is a non-combustible material, so you don't have to worry about fire safety, but it is more difficult to dispose of. This is because the glass wool cannot simply be taken to the waste incinerator, but must be stored in a landfill. This means that there is a price for the disposal of glass wool. This price varies from region to region. Glass wool is partly recyclable and is further processed into new glass wool.

When disposing of glass wool, it is particularly important that it is packed in air-thick bags and sealed.

This is to prevent the dust of the glass wool from spreading and individual parts from being lost.

Are there any health risks when using glass wool?

Proper handling of glass wool reduces health risks, so it is important to consider the points described in the article above. The following table summarises all health risks to give you an idea of how important it is to handle glass wool correctly.

Risk Description
Itching Unprotected contact between skin and glass wool can cause skin irritation such as itching, redness and swelling.
Dust exposure When cutting and laying glass wool, dust can be released which can cause eye irritation, problems and inflammation of the throat and mucous membranes.
Cancer potential As the fibres of glass wool can be inhaled, the risk of cancer is a recurring issue, as mineral substances are classified as "possibly carcinogenic". Since fibres of all kinds can cause cancer. Therefore, glass wool may only be sold if it is not suspected of being carcinogenic and certain conditions must be met for this to happen.

Image source: 123rf.com / 43462628

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