5 minutes min

What is mineral wool?

Mineral wool is the common name for glass wool and stone wool.  

Glass wool has a low weight, is durable and has good strength. It is suitable for soft insulation products, for example between wood and steel lines. The unique characteristics of the glass wool have also made it possible for KIMMCO-ISOVER to develop a complete range of products. Thanks to its excitement and structure, the glass can handle the high demands on load. The glass wool is also used in the form of pipe bowls for insulation of pipes and slabs and carpets for technical insulation. 

Stone wool is often used where the products must meet high operating temperatures or where high fire resistance is required. Stone wool is also used where high compressive strength is required.

Quality and environmental management

KIMMCO-ISOVER quality and environmental management system is certified in accordance with international standards ISO 9001 and ISO 14001.


Mineral wool is made of glass and stone raw material, which is melted and spun into thin threads. On the filaments a binder is cured when the insulation passes through an oven. After curing, the insulation is cut to the right size. Certain products are coated prior to cutting with a surface layer of, for example, paper.

Thermal Conductivity

The primary characteristic of an insulating material is its thermal conductivity, also known as lambda value. The heat conductivity describes the ability to conduct heat. For an insulation material, the value should of course be as low as possible. stone wool & Glass wool, have substantially the same heat conductivity. 

The low heat conductivity of stone wool & Glass wool is related to the ability of the products to keep the air in the insulation still and to reduce heat radiation. 

Heat conductivity is measured in W / m · K. For building insulation, heat conductivity is always stated at an average temperature of + 24 ° C. It varies between 0.032 and 0.039 W / m ° C depending on product.

For technical insulation we indicate heat conductivity at several temperatures in our product descriptions. This is because heat conductivity increases as temperature increases due to increased thermal radiation.

Thermal resistance

If you know the thickness of an insulation product, its heat resistance can be calculated. The greater the heat resistance, the better the insulation. For flat products, the thermal resistance is calculated as the insulation thickness in meters divided by the thermal conductivity in W / m · K.

fire properties

KIMMCO-ISOVER's stone wool & Glass wool products are classified as non-combustible materials (Euroclass A1 or A2) with a few exceptions. Product presentations show the fire characteristics of each product.

dimensional stability

stone wool & Glass wool are materials with good dimensional stability. It is especially important in buildings that are exposed to high temperature variations, such as low-temperature roofs.

Compressive strength

Our product descriptions show the long-term load which yields a maximum of 5% deformation. The products should not be exposed to longer-term loads. 

NOTE: Do not confuse these values ​​with the compressive strength indicated on the labels for CE-marked products. On these labels there is a short-term value that gives 10% deformation and that value should not be used when dimensioning long-term load.


Lightweight glass wool products can be compressed to less than one fifth of their original volume, which reduces the need for environmental impacts. The products are easier to handle and require less storage space.


KIMMCO-ISOVER mineral wool is also used for air-sound insulation of partitions and intermediate floors. In these building parts, a low density insulation product is placed between rails or beams. On these lines or beams, heavy surface materials, such as plasterboard or particleboard, are placed. Notice that mineral wool does not need high density.

Sound absorption

The open porous structure of mineral wool provides very good sound absorbing properties. The absorption factor varies with the frequency. In the middle and high frequency range, the absorption is good already at low thickness. Increased thickness improves absorption in general, but most in the low frequency range. For technical isolation, the absorption factor is shown in the respective product presentation.

moisture properties

Mineral wool products are diffusion openings. This means that water vapor easily walks through them. The products do not suck water capillaryly and do not absorb moisture from the air. 

Water that has entered the products through rain or droughts will dry out if the insulation is stored dry and airy. The products then regain their original insulation ability. If the penetrating water has been contaminated there is a risk that the contaminants will remain in the insulation and for this reason the product may need to be discarded.


Electrolytic corrosion requires an electric current to be led from one part of a metal surface to another. This can only happen if the insulation is water-drained or moist. Mineral wool is water repellent and lacks hygroscopic and capillary trends.


When storing outdoors, mineral wool must be protected from moisture. If the products get wet, there is a risk of moisture build-in in the finished structure, which increases the amount of building moisture. In some cases, building moisture can cause damage to the building.

Certificate and type-approval certificate

KIMMCO-ISOVER has a number of certificates and approval certificates regarding its products, mainly regarding heat conductivity and fire properties.