Mineral Wool Insulation

Mineral wool is any fibrous material formed by spinning or drawing molten mineral or stone materials such as slag and ceramics. Mineral wool is also known as mineral fiber, man-made mineral fiber, and man-made vitreous fiber. Specific mineral wool products are stone wool, slag wool and glass wool which, together with ceramic fiber, are completely man-made fibers.

Properties of Mineral Wool

Sound Absorption

Mineral Wool Insulation

The energy of sound waves absorbed by Rock wool and Glass wool fibers due to the crisscrossed fibers and air pockets. This structure makes Rock wool and Glass wool one of the best sound absorbing insulation for building and industrial applications. Besides the advantage of light weight, Rock wool can also be used to control vibrations caused by sources such as traffic, ventilating systems, heavy machines or similar.

Fire Resistance

Rock wool and Glass wool fibers can resist temperatures of over 750°C for Rock wool and 400°C for Glass wool. Rock wool retains both its thermal conductivity and fire protection capability even when temperatures, as in the case of fire, reach over 900 °C. Therefore, in fire protection applications it should be fixed in such a way as to ensure that they retain their positioning and shape, even after the binder has evaporated because of fire.


The orientation of Rock wool fibers provides very good mechanical properties as well as excellent stability, no thermal expansion or contraction because of the open cell structure. Air pockets allow vapor to get through easily, while also having excellent thermal conductivity. The short fiber length of Rock wool also offers the possibility of making higher density products with a much higher capacity load than other materials.

Water Repellant

That moisture inside insulation reduces thermal conductivity performance. When exposed to water or rain, Rock wool can sometimes look like it is wet throughout. In fact water does not penetrate the product.
Even if water is going into the core of Rock wool or Glass wool, after a certain time the water evaporates and the fibers dry out, as the material is itself diffusing. After drying out, the product completely recovers its properties.

Thermal Conductivity

Thermal conductivity λ varies depending on the temperature of the element to be insulated. At normal temperatures Rock wool has a thermal conductivity between 0,035 and 0,040 W/mK. The advantage of Rock wool over other insulation materials is preserving its properties for a long time, even during serious fire. This capability prevents other materials behind the Rock wool from overheating or even self-igniting.


Mineral wool fibers are inorganic biologically inert materials made out of natural igneous rocks – in addition to sand and silica in case of Glass wool – which forms an unfavorable medium for the growth of fungi, bacteria, vermin, and pests. These fibers are also free of asbestos


Mineral wool fibers consist of natural, chemically-inert fibers forming an open-cell structure that maintains its characteristics with time, implying easy handling and hassle-free storage

Glass Wool Insulation

Glass wool is made of sand, recycled glass, limestone and soda ash. These are the same ingredients that are used to make familiar glass objects such as window panes or glass bottles. The glass is spun to form millions of fine fibers.

Main Application

  • Loft insulation
  • Cavity wall insulation
  • Sound insulation (absorption) within partitions and floors

Rock Wool Insulation

Rock wool is mainly made of volcanic rock, typically basalt and/or dolomite. An increasing proportion is composed of recycled materials made from slag, and a waste product made from blast furnaces.

Main Application

  • Thermal insulation
  • Fire resistance
  • High temperature applications
  • Acoustic insulation
  • High compressive strength applications
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