Origins of aerated concrete

Originally known as cellular concrete, aerated concrete was first produced in Scandinavia in 1924 by Messrs Christiani & Nielson. The following year, after the product had been rapidly adopted throughout the region, they introduced cellular concrete to the UK. Cellular concrete was first made on site and was produced from Portland cement, water and a foaming agent. After mixing it was poured directly into the required position. It was used primarily for insulating roof screeds and underground pipe insulation and in certain circumstances for insulating floor screeds. These remained the only uses of cellular concrete for the next 25 years.

Celcon

In 1949 Celcon Limited was established to develop the uses of aerated concrete. In the early 1950s the development of the Autoclave allowed cellular concrete to be produced in block format. Progress was again made in the mid 1950s when Danish scientists added pulverised fuel ash (PFA), a waste product from coal-fired power stations, to give the product strength yet make it light enough to pick up with one hand. Celcon's production in the early days was in small tin and timber sheds with experimental and often homemade equipment. Production and handling were very labour intensive, often done in open areas that were exposed to the elements.

The company develops

In 1958 a factory was built at Grays, Essex, for the production of precast aerated concrete blocks and screeds. This was made possible by the association between Celcon Limited, Christiani & Nielson and Dansk Gasbeton of Denmark. However in 1963 the association with Christiani & Nielson ended with Dansk acquiring the controlling interest in Celcon along with the Board of Directors, and other British interests. As a new concept that went against traditional British building methods, the product was viewed with apprehension, with the factory's output mainly meeting the demand arising from the activities of the parent company, contractors Christiani & Nielson. However as the industry began to see the advantages of using aircrete blocks, demand increased throughout the UK. In 1966 Celcon Limited opened a second works at Rugeley in Staffordshire to supply the Midlands area, and in 1974 they moved into the West Country, opening a purpose-built factory at Westbury. The UK coverage was completed in 1978 with a factory built at Pollington in Humberside (now East Yorkshire). In 1992, at the depth of the last major recession to hit the UK building industry, the Rugely factory was closed. However, a new state-of-the-art factory at Borough Green, Kent, started production to replace the output of the original plant in Greys (which was to close in 1995). Although aircrete products have been available in the UK for over 50 years, it is still seen by many as a 'new' product. Indeed, as with many new products, aircrete as a building material has much more to offer than is being utilized today. Celcon products are yet again at the forefront of innovation in masonry construction. During the late 1990s the Celcon Thin-Joint System was launched with its own brand of mortar called Celfix. This new approach to aircrete masonry enables huge productivity savings and provides the potential for significant increases in build quality.

Expansion in UK and Scandinavia

During 1999 Celcon got closer to its holding company, now called 'H+H International A/S'. Following the change, the holding company purchased aircrete manufacturing plants in Finland and Norway, whilst setting up a sales operation in Sweden. This enabled H+H in the UK to benefit from the experiences and product development in the Scandinavian countries, leading to innovations and exciting new products. In order to respond to the growing demand for higher quality products and innovative new building systems a new plant has now been built on our Pollington site in Yorkshire. Designed to manufacture the Plus block range, this factory utilises some of the most advanced and environmentally friendly manufacturing equipment for the production of aircrete. Pollington 2, as the factory is known, was officially opened by Brian Wilson, Minister of State for Energy and Construction, on the 11th March 2003.