From our first stone wool production in 1937 to the extensive range of solutions we supply today, ROCKWOOL Group products have evolved to enhance many aspects of modern life.
The ROCKWOOL Foundation was established in 1981 by Claus Kähler and his five siblings. Each donated shares from their own holdings to ensure that the Foundation – at that time owning 25 percent of all shares – would be a major shareholder and have a major say in the future development of the ROCKWOOL Group. The Foundation is an independent and financially self-supporting organisation, which aims to generate knowledge that can help tackle problems facing society today. It achieves this through impartial scientific research into social and economic issues, and by carrying out practical interventions. The Foundation’s work is particularly focused on issues related to the sustainability of the welfare society. Research is conducted by both the ROCKWOOL Foundation’s Research Unit and specialist external researchers, while practical interventions are managed by the Foundation’s Interventions Unit.
In 1982, fibres with even higher temperature stability were created, forming the basis for today’s high-temperature, bio-soluble stone wool. The new development used the high-temperature properties of the Spinrock fibre developed in the 1970s to set new standards in the market.
CONROCK A/S was established in 1985 to drive radical innovation and to serve as an incubator, using a small, agile organisation to develop and market new products for purposes beyond thermal insulation. Among CONROCK’s innovations were the Conlit product line, used for fire protection in buildings and Rocklit, a high-density board marketed today as Rockpanel. Both were the basis for successful product lines and businesses. Also in 1985, Spinrock fibre production was moved to the Netherlands and later, a separate business Lapinus Fibres (today Lapinus) was established. Today, the Lapinus portfolio includes some of the newest solutions addressing modern society’s challenges, such as urban water management.
From 1981 to 1988, the ROCKWOOL Group also marketed tailor-made moulded components under the Rockform name, for applications such as noise insulation in vacuum cleaners, the insulation of hot objects in natural gas ovens and recessed lighting in ships. The learnings from this business line were used to develop other ROCKWOOL Group applications including acoustic ceilings, façade claddings and hydroponic growing solutions.
In 1987, Tom Kähler was appointed CEO, succeeding his father as Managing Director of ROCKWOOL International A/S. As CEO and at a later stage Chairman of the Board, Tom cemented ROCKWOOL’s role as a global player in the insulation business when the Group also started building its business in Russia and Asia. The number of countries with ROCKWOOL production facilities grew from six to 14 during Tom’s 17-year tenure as CEO, paving the way for further business development and geographical expansion.
In 1980, ROCKWOOL Isolation S.A. was established with a sales office in Paris and a factory in Saint-Éloy-les-Mines, and in 1985 the factory in Hiltrup, Germany was acquired, and the sales office in Austria was established. Offices were set up in Italy and in Spain in 1989. In 1988, ROXUL Inc. was established in Toronto, Canada. In the following years, four additional factories were built in the US and in Canada, and ROCKWOOL’s position grew significantly. With five factories and 1,000 employees, ROXUL has become North America’s largest stone wool producer, offering advanced building insulation, industrial and technical solutions.
Constantly optimising the ROCKWOOL mineral fibre technology and pursuing new ideas have always been key priorities for the Group R&D organisation. In the 1970s, this led to the development of a fibre that could replace asbestos to reinforce materials and products such as bitumen, paints, adhesives and brackets. Launched in 1974, Spinrock Fibres were a radical innovation for the 1970s, demonstrating how looking for healthier, more sustainable and environmentally friendly products has always been part of ROCKWOOL’s DNA.
In 1976, ROCKWOOL International A/S was set up as a holding company for the entire Group, during a decade that saw the business develop and expand significantly. In 1970, 50 percent of the shares of the Nederlandse Steewolfabrik in Roermond in the Netherlands were acquired, with the remaining 50 percent purchased in 1975. Also that year, 50 percent of the shares in ROCKWOOL AB are sold to the Swedish State, which already owned the other 50 percent. In 1977, the factory in Doense began operations and in 1978 the subsidiaries Grodania and Rockfon were set up. The end of the decade, 1979, saw the establishment of ROCKWOOL Limited in Bridgend, UK.
Tom Kähler was employed as Director for emerging enterprises in 1978 and became CEO in 1987, a position he held until 2004, when Eelco van Heel was appointed COO as part of a succession plan. Tom became Chairman of the Board in 2004. Before joining the ROCKWOOL Group in 1978, Tom Kähler worked for several companies after completing his education as civil engineer, including setting up Ecoterm, his own contracting company, with his brother-in-law Keld Jepsen. Tom played a key role when ROCKWOOL Group established itself in Canada and made its first real entrance in the North American stone wool insulation market.
The development in the early 1970s of Spinrock fibres, which helped industries to replace asbestos,
led to ROCKWOOL’s recycling concept. Plant workers in Hedehusene found that old stone wool products could be recycled if they were ground and mixed into briquettes. The first briquettes were made in 1978 for Spinrock and in 1979, this process was tested and implemented in the plant in Hedehusene, creating the foundation for a comprehensive “circularity” concept. The recycling of ROCKWOOL Group’s own production waste was extended further in subsequent years, to cover recycling schemes for external construction waste and demolition waste.
Built during the second oil crisis of 1978-1980, the Hjortekær low-energy test houses in Denmark showed that with good workmanship, careful design and good insulation, the energy use of a building could be reduced to one-tenth of contemporary standards. The ROCKWOOL Group was a key contributor to this project.
In 1962, I/S Kähler & Co was founded, with wholly or partly-owned limited companies in Denmark, Norway, Sweden and Germany. Later that decade, expansion continued with the acquisition of a factory in Moss, Norway in 1965 and the start of operations at the greenfield factory in Vamdrup, Denmark in 1966. Three years later, in 1969, the company signed a licence agreement with FLUMROC AG of Switzerland, and acquired 26 percent of its shares.
In 1962, the Kähler and Henriksen families agreed to split and establish two new companies. Jens Nørgaard, later to become CFO of the ROCKWOOL Group, proposed a new company structure with the ROCKWOOL activities in one group and all others – sand pits, the aerated concrete business and Hasle tiles – in another group. The Henriksen family then chose the group they preferred and the company’s activities were split accordingly. On 1 January 1962, the name was changed to I/S Kähler & Co., with the Kähler family taking sole responsibility for the ROCKWOOL business.
Acoustic insulation products marketed under the Rockfon brand were introduced in 1962 and would grow into the second-largest business activity in the ROCKWOOL portfolio. In 1968, a collaboration with Horticulturist O. Bagge Olsen led to the development of stone wool as a growing medium for the professional horticultural sector, based on Precision Growing principles. Established in 1969, the Grodan business is active today in more than 60 countries worldwide.
On 2 April 1968 Horticulturist O. Bagge Olsen from the Danish Agricultural University (Landbohøjskolen) in Copenhagen met with ROCKWOOL employees Svein Melhus, Helge Høyer and J. Skjold Petersen to discuss the use of stone wool as an additive to sphagnum. For many years, O. Bagge Olsen had investigated the relationship between stone and crops, finding that plants grew particularly well in areas with a lot of basalt in the soil. A joint development project and a test program involving local cucumber grower Viggo Nielsen created the basis for developing the current Grodan business.
Claus Kähler began his career managing stone wool production, aerated concrete and the gravel pits in 1948. By that time, 82 people were employed in Hedehusene, with all operations run by one organisation. In the 1950s, Claus set up separate production entities and created the basis for future profitable growth: in Denmark, turnover expanded from DKK 2.5 million to DKK 20 million during the decade and technological expertise grew significantly. Claus Kähler became CEO of Henriksen & Kähler in 1958, holding the position for 22 years.
In 1952, ROCKWOOL acquired the licence from Johns Manville in the USA to use spinners for drawing fibres. The new process used diabase rock instead of slag, creating fewer shots (small pieces of stone that have not been spun into fibres), lower densities and more robust fibres. The result was wool with a significantly higher and more homogeneous quality. In 1953, the 4-wheel spinner was introduced, dramatically increasing potential output, which has grown from 0.6 tonnes per hour in the early 1950s to over 20 tonnes per hour today. The year 1954 was a turning point, as production with added binder worked smoothly and the quantity of slabs produced overtook sewn mat products. Mat products however continued to be an important part of the product portfolio and in 1959, ROCKWOOL acquired a patent covering lamella mats for pipe insulation.
Deep knowledge of core technologies has always been key to ROCKWOOL’s success. To build on this, the company set up its own engineering department in Hedehusene, with five employees.
In 1954, ROCKWOOL established its first non-Scandinavian subsidiary in Germany. In 1958, the headquarters moved from Korsør to Hedehusene and expansion continued in 1959 with the opening of a second factory in Trondheim, Norway.