A tale of stone

Our heritage

A tale of stone

logo, 80th anniversary, rockwool, germany


80th birthday

This year, at ROCKWOOL Group we celebrate 80 years since our founders first produced stone wool in Hedehusene, Denmark, where we are still headquartered today. Continuity like this is unusual in the business world. Why have we endured so long? It’s because ever since we were founded, we’ve had one single-minded purpose: unlocking the unique strengths of stone to enrich modern living. Everything we do is organised around this ambition.

Jens Birgersson (3)


A new CEO arrives

The appointment of Jens Birgersson as CEO of the ROCKWOOL Group marked a renewed focus on business efficiency, including the subsequent launch of wide-ranging business transformation program to clarify roles and responsibilities, reduce internal complexity, leverage our scale and strengths by utilising best practices, and becoming even more customer focused. In 2016, the Group launched its new Purpose: Releasing the natural power of stone to enrich modern living. The purpose outlines the ROCKWOOL Group commitments and contributions to society. We are committed to empowering everyone to rise to the development challenges of modern living. By using stone, one of the world's most abundant natural resources, we can make a lasting impact across generations. From classrooms to stadiums, land to landmarks, people need spaces to dream big – and to act on those dreams, making the world a better place for everyone.

Eelco van Heel - was appointed Deputy Group President and head of the Executive Committee in 2001


Growth in Russia and America

The year 2010 saw the acquisition of a Russian factory in Troitsk as well as purchase of an Asian insulation business from the Australian Group CSR Ltd. In the same year the ETICS (External Thermal Insulation Composite System) business was further developed and in 2011, FAST, a Polish producer of render for ETICS, was acquired. In 2012, a new factory was built in Elabuga, Russia, and in 2014, the American ceiling grid producer Chicago Metallic and the German ETICS system holder HECK Wall Systems are acquired. Greenfield production facilities were built in Mississippi (US) in 2014, and in 2017, it was announced that a second manufacturing plant will be built in West Virginia (US)

To be updated


Health and safety of ROCKWOOL products confirmed

In 2001, the International Agency for Research on Cancer (IARC) classified rock (stone) wool insulation as Group 3: not classifiable carcinogenic in humans. This was valid both for old and the new HT (high temperature) fibres. The IARC (the World Health Organisation’s cancer research institute) re-evaluated the thousands of existing health investigations on stone wool in production or in use. Due to its high bio-solubility, the fibre used in ROCKWOOL stone wool insulation materials was assessed as free from carcinogenic effects.

To be updated


Further ROCKWOOL Group expansion

In 2000, a factory in Malacca, Malaysia was acquired and a greenfield factory in Caparosso in Spain taken into operation. The year 2004 saw the purchase of the Hungarian Isolyth factory and buildings were acquired in Vyborg in Russia with a view to building manufacturing plant. In 2005, the decision was taken to build a greenfield plant in Croatia. A year later, in 2006, the new factory in Cigacice, Poland was inaugurated, and in 2008, the decision to build a new factory in Gujarat in India was taken.

RockWorld imagery, The big picture, water,  factory, sky


Focus on energy efficiency

The Kyoto protocol was the first agreement among nations to mandate country-by-country reductions in greenhouse gas emissions. Kyoto emerged from the UN Framework Convention on Climate Change (UNFCCC), which was signed by nearly all countries at the 1992 meeting popularly known as the Earth Summit. This was a key milestone in ROCKWOOL’s history, creating awareness of how insulation can contribute to significant reductions in CO2 emissions. It also initiated a debate in the EU about how to reduce energy consumption and energy dependency. This resulted in an EU paper presented in 2000, which for the first time documented that 40.3 percent of total energy consumption in the bloc comes from buildings.

To be updated


Strategic focus on technology and R&D leadership

In 1992, a HQ Group Technology function was established, responsible for global coordination of production, environment, investments, logistics, R&D, norms and standards, patents, and engineering – everything to do with the design and construction of manufacturing equipment, production lines and plants. This solidified the foundation for ROCKWOOL’s strong global leadership in stone wool.

To be updated


The ROCKWOOL Group becomes a listed company

In 1996, ROCKWOOL International was listed on the stock exchange at Nasdaq Copenhagen. The Company’s shares were listed in two classes – ROCKWOOL A and ROCKWOOL B. Each A share carries 10 votes, while each B share carries one vote. The ROCKWOOL Foundation today owns 23 percent of the ROCKWOOL Group, making it the largest shareholder.

To be updated


Expansion eastward and beyond

In 1999, the Russian factory near Moscow was acquired; the same year in which the Canadian factory in Grand Forks and the Italian factory in Sardinia (which was later closed) were acquired. Prior to the expansion in Russia the factory in Eastern Germany was acquired in 1991. In 1993 and 1995 two factories in Poland were acquired, in Cigacice and Malkinia; a factory in Goganfa, Hungary was acquired in 1997; and in the Czech Republic, a factory in Bohumin was purchased in 1998. Rockfon production started in 1992 in Saint-Éloy-les-Mines, France, and in 1997, Rockdelta was established, offering solutions for vibration and noise control.

The Rockwool Foundation


The ROCKWOOL Foundation

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.

To be updated


New generation of stone wool fibres

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.

To be updated


Driving innovation

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.

To be updated


Rockform moulded components

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.

To be updated


Tom Kähler becomes CEO

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.

To be updated


Expansion through Europe and North America

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.

Development meeting 1985


Always innovating

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.

To be updated


ROCKWOOL International A/S founded

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.

To be updated


Tom Kähler: the next generation takes over

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.

To be updated


Circular thinking

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.

To be updated


Demonstration projects

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.

TBS (In translation)


I/S Kähler & Co founded; expansion continues

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.

Jens Nørgaard - personal assistans to Claus Kähler. He was deeply involved in the proposal of splitting up the company in the early 1960s.


The Kähler family takes sole responsibility for the ROCKWOOL business

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.

Grodan & Rockfon logo


Rockfon and Grodan created

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 70 countries worldwide.

To be updated


The power of partnership

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 later to be CEO for 24 years, was employed in 1948.


Claus Kähler, 22 years as CEO

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.

To be updated


First use of spinning technology

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.

ROCKWOOL Laboratory management 1963


ROCKWOOL engineering department founded

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.

To be updated


Geographical expansion

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.

Inspector Jørgensen


Inspector Jørgensen, innovator

During World War II, Inspector Jørgensen found innovative ways to get round the scarcity of raw materials. To keep production going he substituted peat briquettes for oil, used skimmed milk instead of oil for water repellence and replaced cotton with paper thread for sewing stone wool mats.

Verner Palmqvist - started in 1941 at the age of 24 as an electrician and retired 44 years later as Vice President of Research & Development. The photo shows him next to one of the productions lines in Hedehusene ind 1958.


Verner Palmquist, innovator

Working with ROCKWOOL from 1941-85, Verner Palmquist joined as an electrician and went on to become Technical Director and head of R&D. During his career, he shared in some the group’s major developments. Verner was promoted to Technical Director following his involvement in the successful transition from steam-blown wool to spun stone wool. His curiosity and experiments led to the use of binder and the transition from loose stone wool to the wide range of products that we know today.

Factory workers 1940


Binder expands stone wool’s potential

ROCKWOOL acquired the licence from Baldwin Hill to add binder to the stone wool, making it possible to develop products with good dimensional stability. This change significantly expanded the ROCKWOOL product portfolio, creating a foundation for today’s diverse product range.

Gustav Kähler (Partner: 1916-1958)


Gustav Kähler, engineer and manager

In 1948, Gustav Kähler was appointed Managing Director I/S Henriksen & Kähler and his son Claus Kähler became Deputy Director, responsible for operations. Ten years later, Claus Kähler became CEO. Gustav started his career in his father Valdemar Kähler’s company I/S H.J. Henriksen and V. Kähler in 1915 as a civil engineer, long before stone wool production began. Succeeding his father as partner in 1916, he played a vital role in the expansion of the business geographically as well into new areas, including stone wool.

The wool chamber in the late 1930s.


Stone wool production licenced

I/S Henriksen and Kähler acquired the licence to produce stone wool in Denmark, Norway, Sweden and Germany from New Jersey, USA-based Baldwin-Hill. The production process, based at the time on steam-blown fibres, was used to make loose wool and sewn mat products. It was a further 17 years before the more efficient and versatile spun wool production process was introduced.

Finn Henriksen was on a study tour to the US and saw a good opportunity to use the company's stone deposits for stone wool production.


Finn Henriksen, inspired by a study tour

The son of [industrialist] H.J. Henriksen, Finn Henriksen saw stone wool production during a study tour to the USA. On his return to Denmark, he joined I/S Henriksen and Kähler established by his father and Valdemar Kähler, which invested USD 5,000 to licence stone wool technology from Baldwin-Hill. The foundation of ROCKWOOL Group stone wool production was laid.

Production at the Factory in Hedehusene late 1930.


Stone wool production in Denmark

The stone wool plant in Hedehusene, Denmark, began production. It burned down in 1938 but was rebuilt the same year. Also that same year, production of ROCKWOOL mineral wool began in Skövde in Sweden and Larvik in Norway. By 1939, total production had risen to 2,000 tonnes per year in Hedehusene alone.