Rock wool boards WLS 035 – 040
Insulation boards
Plaatisolatiematerialen
Plattendämmstoffe
Mats for thermal insulation
Mattenisolatiematerialen
Mattendämmstoffe
Loose-fill and blow-in insulation materials
Stort- en inblaasisolatiematerialen
Schütt- und Einblasdämmstoffe
Speciality products
Speciale producten
Spezialprodukte
Eigenschaften
Like all mineral wool products, rock wool boards are non-combustible (building material class A1) and offer high fire resistance, which is an advantage over most other insulation materials. Owing to these properties, as well as their good thermal and sound insulation qualities, they are well suited for insulation in building construction. In addition, rock wool panels have a long service life and are resistant to mould and rot.
Rock wool boards can be used in a wide range of applications: flat roof insulation, between-rafter and on-rafter insulation, external thermal insulation composite systems (ETICS), ventilated façades, internal insulation systems, timber frame construction, lightweight partition walls and impact sound insulation in buildings. Installation is generally straightforward, as the boards can be cut to size with a sharp knife. As with all indoor work, care must be taken to wear suitable workwear to protect against any dust generated.
Rohstoffe und Herstellungsverfahren
Raw materials: diabase, basalt, dolomite, phonolite and recycled rock wool, small quantities of binding agents and, where applicable, water-repellent agents, as well as other (secondary) raw materials
The mineral raw materials and recycled materials are melted at a temperature of approximately 1500 °C and defibrated using a centrifugal or jet-blowing process. This process is comparable to the natural activity of a volcano: when a volcano erupts and a fountain of lava is formed, the wind draws thin strands from the lava: natural mineral wool.
Spinning process: Here, a jet of the still-molten mass strikes rapidly rotating flywheels and is spun into fibres by the rotational movement. Nozzle-blowing process: After passing through the melting tank, the molten glass flows through numerous nozzles. This produces strands which are then drawn into fibres using compressed air.
In the next step, a small amount of an aqueous binder, dust-binding oil and, where necessary, a water-repellent agent is added to ensure stability and water-repellent properties. This is followed by heating to cure the binder and, finally, the cutting to size and packaging of the finished rock wool boards.
Technical Specifications
Property | Unit | Parameters | ||
|---|---|---|---|---|
| Thermal conductivity λR | W/(mK) | 0.035 | 0.040 | |
| Bulk density ρ | kg/m³ | 60–120 | 120–180 | |
| Heat capacity c | J/(kgK) | 840–1030 | 840–1030 | |
| Building material class | -- | A1 | A1 | |
| Water vapour diffusion resistance μ | -- | 1 | 1 | |
| Primary energy content | kWh/m³ | 310–506 | 310–506 | |
| Water-repellent effect | -- | Depends on product | ||
| Can it withstand pressure? | -- | Yes | Yes | |
Insulation materials made from mineral wool, including rock wool, are recyclable products. Provided the boards are of a single type and largely free from foreign substances (e.g. adhesive, plaster, mortar), the rock wool can be remelted and processed into new rock wool. Where permitted, rock wool products can also be reused. Otherwise, they can be disposed of in landfill. Recycling in other industries is also possible. For example, rock wool residues can be processed in the brick industry, in fibre-cement boards or in roof tiles.[i]
Thanks to established take-back and recycling schemes, several thousand tonnes of mineral wool from construction sites and demolition projects are already being recycled into new mineral wool every year, and this figure is rising.
DIN EN 13162 in conjunction with DIN 4108-10, Table 3 (Application-specific requirements for mineral wool thermal insulation materials)
Gesundheit und Ökologie
In Germany, only mineral wool products – namely rock wool and glass wool – that pose no risk to health and are approved in accordance with the Hazardous Substances Ordinance (GefStoffV) and the Chemicals Prohibition Ordinance (ChemVerbotsV) may be placed on the market and installed. These products bear the RAL quality mark ‘Mineral Wool Products’, which is awarded by the Gütegemeinschaft Mineralwolle e.V. [ii] The Gütegemeinschaft monitors and checks compliance with the certification requirements. The KEYMARK quality mark also certifies the high quality of mineral wool insulation materials.
The short transport distances and the good availability of raw materials are environmentally beneficial. Other positive aspects include the long service life of rock wool insulation materials, as well as waste-free production and the already established recycling options. Furthermore, manufacturers are continuously working to optimise their production processes and reduce associated CO₂ emissions.
[i] ENVIRONMENTAL PRODUCT DECLARATION in accordance with ISO 14025 and EN 15804+A2: Mineral wool insulation in the high bulk density range, FMI Fachverband Mineralwolleindustrie e.V., 29 June 2023: https://www.der-daemmstoff.de/wp-content/uploads/2023/07/Mineralwolle-Daemmstoff-im-hohen-Rohdichtebereich_EN15804A2.pdf (accessed on 11 December 2025)
[ii] Gütegemeinschaft Mineralwolle e.V.: https://www.ral-mineralwolle.de (accessed on 3 July 2024)
- numerous areas of application, also suitable for ETICS
- Extensive experience with this insulation material; readily available
- Good availability of raw materials
- Short transport distances; a regional product
- Competitive pricing
- Non-combustible (A1)
- Good sound insulation
- Long service life
- High compressive strength, depending on the product
- Recyclable or reusable (clean, single-grade rock wool)
- Energy consumption during production must be reduced further