Rockwool

History

Rockwool was founded as Korsør Stenforretning by constructor Henrik Johan Henriksen and brickyard-owner Valdemar Kähler in 1909 as a gravel mining company. In 1922, the company won the contract on improving the dykes at Saltbæk Vig and later purchased the area.

In 1927, it purchased a chipping plant at Hedehusene. In 1937, a production of mineral wool (stone wool) was established at the site based on an American license acquired by Finn Henriksen during a visit to the States. By 1939, the focus of the company had fully turned toward the manufacture of insulation.

In 1972, the company was divided into H+H and I/S Kähler & Co. Kähler & Co. was led by Valdemar Kähler's grand son Claus Kähler. He was succeeded on the post by his son Tom Kähler in 1986. In 2004, Tom became chairman of the board while Eelco van Heel took over the position as chief executive officer.

The company began trading as "Rockwool International A/S" on the Copenhagen Stock Exchange in 1995. Before it became a public company, it was a family-owned business, held by the Kähler family.

The company's first plant in the United States opened in 2014 in Marshall County, Mississippi. In 2017, the company announced a North American expansion through establishment of a plant in Ranson, West Virginia through its subsidiary Roxul.

In 2023 Rockwool was named an "International Sponsors of War" by Ukraine for selling products to the Russian Ministry of Defence for use on warships.

In January 2026, the company announced that Russia had taken control of four factories on Russian territory. According to Rockwool, the value of the nationalized factories was $469 million.

Rockwool Foundation

In 1981, six members of the Kähler family established the Rockwool Foundation with an endowment of 25% of each of their own stock holdings in Rockwool International. The Foundation has been referred to as a think tank by some authors. The Rockwool Foundation Research Unit was established as a fully independent unit with a focus on social science research in 1987 by the Foundation, led since 2003 by Torbin Tranæs. The Research Unit has been described as self-financed and non-partisan. The Research Unit has published on topics such as the extent of the financial black market in Denmark. In other published cases, it has been unclear whether the Research Unit or the Foundation have been the actor, as in the case of examining the British health care system with an eye toward the financial cost of emulating the Kaiser Permanente system, and an analysis of the impact on the Danish economy of wages lost through prisoner incarceration.

Brands

Rockfon

Rockfon is a brand of acoustic ceiling and wall solutions based on rockwool.

Flumroc

In 1969, Rockwool acquired a minority stake related to technology licensing in the privately held Swiss company Flumroc AG. In November 2017 Rockwool completed acquisition of all outstanding shares of Flumroc; company sales have been largely limited to Switzerland. Due to the broad recognition of the brand in Switzerland, Rockwool kept using the Flumroc brand.

Roxul

With the acquisition of a stone wool factory in Ontario, Canada, Roxul Inc. was established as the Canadian subsidiary. When business started in the United States, Roxul USA Inc. was established as the US subsidiary. On 1 January 2018, the North American insulation business rebranded to ROCKWOOL North America.

Locations

Rockwool International is represented in 38 countries (2016), operating 28 factories in the following countries: