History

The beginnings

Chemist Dr. Carl Grünzweig and businessman Paul Hartmann founded their “Fabrik chemisch-technischer Producte von Grünzweig & Hartmann oHG” on 1 September 1878 on today’s Frankenthaler Strasse in Ludwigshafen. Their main objective was to develop new insulation for cutting-edge systems and machinery to replace traditional insulating materials such as straw, chaff and animal fur.

The young company received its first patent as early as 1880, for insulating boards made of cork. Shortly afterwards Carl Grünzweig developed diatomite stone from kieselguhr. This was an insulating material able to withstand high temperatures, e.g. for boilers in power plants and ships.

The factory, which now had its own assembly team, expanded rapidly. In 1890, the company already had more than 100 employees. In 1908 it set up branches in Berlin, Düsseldorf, Hamburg, Dresden, Munich, the Vienna region and Budapest, and established licensed factories in the UK and the U.S. Founder Paul Hartmann died in 1899. In 1906, Grünzweig’s son Max made a revolutionary discovery. He found that heating the cork granulate without adding air caused it to expand significantly. This made the cork boards much lighter - the new insulating material Expansit was born.

This discovery also benefited the brewing industry. Alongside the newly-developed ammonia refrigeration cooling system, this cork insulating board made it possible to store beer all year round at low cost, thus eliminating the need for the ban on brewing during the summer months.

Setbacks and new beginnings

A huge fire on the company premises in 1912 was a major setback for Grünzweig & Hartmann. It destroyed many buildings and a large amount of stock. They rebuilt the raw cork warehouse at the municipal harbor.

Carl Grünzweig died in 1913 aged 68, and his son Max was only able to take the helm until 1919. Civil engineer Michael was then appointed as the new managing director. Under his leadership, the company created the famous cork tower 
- a combination of water tower and granulate silo - in Ludwigshafen in 1914.

The development of the “continuous cork board machine” made it possible to increase cork board production significantly to 70,000 cubic meters a year. Due to the high demand, the company extended its raw cork imports to North Africa.

The competition hotted up in the 1930s with the foundation of Glaswatte GmbH in Bergisch Gladbach in 1931, which became Glasfaser GmbH in 1937. In later years, this company would go on to merge with G+H. In 1939 Grünzweig & Hartmann showed that they could hold their own in the face of this competition by applying for a patent for a new fiber insulating material - the mineral fiber Sillan®, named after silicon and “lana”, the Latin name for wool. The company built two new plants for the production of Sillan®.

The Second World War also left its mark on Grünzweig & Hartmann, with the plant in Ludwigshafen being almost completely destroyed by a series of U.S. bombings from September 1943. Only the cork tower, the emblem of G+H, managed to survive virtually unscathed.

Reconstruction

After the end of the Second World War, the remaining workforce started to rebuild the company, a process which lasted until 1951. Raw materials and loans were hard to come by at this time, but they succeeded in getting the cork business up and running by May 1945. And Sillan® production was underway again by March 1946.

In 1947, Dr. Fernholz took over as chairman of the company management. At this time, the company’s portfolio of cold and heat insulation was expanded to include products from the sound insulation sector. The product range now also included impact-sound insulation and sound-absorbing panels for suspended ceilings and flat and industrial roofs.

By 1950, the company had a workforce of 1,350 and was generating annual sales of around 19.5 million German marks. Two years later, Grünzweig & Hartmann GmbH was converted to a public limited company (Aktiengesellschaft).

The company’s 75th anniversary in 1953 concluded with the official start-up of the Sillan® system V, the first since the War. And things continued to go well for the company. As towns and cities in Germany began to be rebuilt after the war, the demand for insulating materials rose accordingly. In 1956, Grünzweig & Hartmann purchased factory premises in Ladenburg near Heidelberg spanning 80,000 square meters. And the company issued an increasing number of product licenses abroad, e.g. in Scotland, Italy, Argentina, Holland and France.

Mergers and expansion

The company set up a new pillar of operations at the end of the 1950s by kick-starting the production of Exporit® from Styropor®. Alongside rigid foam boards for interior work, Exporit® form packaging for fragile goods was a pioneering development that became the material of choice for customers such as Braun and Märklin in the early 1960s.

The company had seen a lot of changes over the years. In 1958, a three-strong team - comprising chairman Dr. Fernholz and two board members Rudolf Klingholz and Robert Maul - was in charge of the company. At the start of the 1960s, Saint-Gobain took over as the majority stockholder. However, competition between Grünzweig & Hartmann and Glasfaser GmbH - a wholly-owned subsidiary of Saint-Gobain - was still fierce.

In 1962, Grünzweig & Hartmann concluded a spectacular project - the construction of the world’s first noise control hall for testing engines built into aircraft at Hamburg Airport. 1968 saw the launch of Rollisol, which soon became the most popular insulating material in Germany.

In 1969, Grünzweig & Hartmann and Glasfaser GmbH jointly founded Unimat Schaumstoff GmbH in Bochum. The collaboration stepped up a gear in 1972 when they joined forces to establish “Grünzweig + Hartmann und Glasfaser AG” under the new chairman Felix Altenhoven. At the time, the new company was the first provider to specialize in products made from both glass wool and rock wool. The company spun off its assembly activities in 1976 in the form of “Grünzweig + Hartmann Montage GmbH”.

Major projects

1988 saw another change in the company structure, with the shares of G+H MONTAGE GmbH passing to the French company Société Générale d’Entreprises (SGE), the structural and civil engineering group of Compagnie Générale des Eaux (later known as VIVENDI).

A few new subsidiaries joined the company in 1990, including Isolierungen Leipzig GmbH and Heinrich Nickel GmbH.

The name of the former parent company also changed from “Grünzweig + Hartmann und Glasfaser AG” to “Grünzweig + Hartmann AG”.

A series of major national and international projects then strengthened the company’s reputation: For example, in 1987 G+H MONTAGE GmbH was awarded a contract worth 100 million German marks to fit out the interior of a concert hall in Taiwan. March 1989 saw the company reach another milestone with G+H taking on interior fitting, fire prevention measures and the heat and sound insulation for the construction of the new “Convention Center” on the grounds of Hannover Messe. G+H fitters were also involved in work on Cologne’s highest building site when the Colonius television tower was extended by 24 meters in April 1990. Overseas building projects included work on the European spaceport in French Guyana, a sodium carbonate and salt extraction plant in South Africa, a refrigerated warehouse in Kamchatka and an international holiday resort in China. What’s more, the company was also involved in the futuristic z-shaped television tower, which was much admired by spectators at the Olympic Games in Barcelona in the summer of 1992. The antenna and antenna platform of this architectural masterpiece featured cladding from G+H.

New structures

In 1996, G+H MONTAGE GmbH was split into the six subsidiaries: heat insulation, cold insulation, noise control, façade construction, interior fitting and shipbuilding. The following year G+H MONTAGE GmbH was added to the “Thermique und Mécanique” branch of Société Générale d’Entreprises, where it was divided into the two divisions Insulation and Structural Engineering.

In December 1996, G+H built a new acoustic measurement room for the automotive industry in the U.S., which was used jointly by Chrysler, General Motors and Ford. The new Mercedes S Class was launched in 1997 with an engine featuring a high-temperature insulating system from G+H ISOLITE.

Over the years, the company’s structure has also been subject to expansion and conversion. In 2000, G+H MONTAGE GmbH was integrated into the Energie-Information (GTIE) sector of Société Générale d’Entreprises, which was then itself renamed VINCI. 2002 marked another stage in the company’s development, when G+H’s Insulation division was incorporated into GTIE Deutschland GmbH, while its Structural Engineering division was merged with VINCI Bautec GmbH. GTIE was renamed VINCI Energies at the start of 2003.

Over the years, G+H has increasingly focused its attention on becoming a service provider for high-tech applications. For example, the Eurofighter EF 2000 was equipped with an ISOLITE high-temperature insulating system. At the end of 2001, Hamburg Airport inaugurated a noise control hall for engine tests on wide-bodied aircraft, which was the first of its kind in the world. G+H Schallschutz played a leading role in its planning, design and construction. The Iso Award 2002 for the fire protection tape Pyrostat®-Uni is proof of how successfully G+H combines innovative ideas with the experience the company has built up over the past 125 years.