Fibre Cement - Rooted in History
This “slurry” was fed into a paper making machine, basically a cylindrical sieve or sieves rotating through the slurry. The solids are deposited on the sieve which on each rotation attracts a layer of the solids and transfers the layer onto a continuous belt. The layers are built up to the desired thickness and then removed and if necessary compressed. This process was patented as the “Eternit” process.
PROPerties OF FIBRE CEMENT
From Eternit to Cembrit
By 1894 Hatschek’s factory Eternit Werke Ludwig Hatschek was manufacturing fibre cement products for sale. Licenses were sold throughout Europe, including to our Danish parent company Dansk Eternit Holding A/S in 1927, one of the proliferation of independent companies entitled to use the “Eternit” trade name. By the time the license expired in 1906 the industry was established. Since 1906 many imitators also were founded who did not use the Eternit license. Over the intervening years many of the fibre-cement manufacturers were acquired by the Belgian Eternit Group, now known as Etex. Dansk Eternit have however always remained independent and marked this fact in 2008 by adopting one of our successful brands, Cembrit, as the new name for the whole Group.
Fibre cement - a building material with many strengths
Man-made PVA fibres have long since replaced the mineral fibre, and other solids are now added to the slurry to furnish different performance characteristics. Colouration is now often incorporated on the surface or in the slurry and extra curing is also undertaken to improve strengths and speed up the process, however the essential heart of the process, the Hatschek machine and the “magical” conversion of a liquid into a solid, remains.
The beauty of fibre-cement as a building material is 4-fold: Fire resistant, rot resistant, malleable during production and low weight.
A flexible building material
Immediately after it is formed fibre-cement is still pliable. This means it can be moulded into 3 dimensional shapes, can be embossed and because the fibre matrix supports the cement and other solids, can be far thinner than concrete. Random and natural surface effects can be achieved but with the consistency of a production line giving superb levels of control and cost efficiency. By the simple formation of a repeated wave in the wet material, larger panels can be made self-supporting and thereby provide excellent method of cladding large areas.
Fibre cement is a light weight building material
The hydration process means the material gets progressively stronger, providing concrete like strength but at a much lower weight. The advantage is that a lightweight sheet can be produced which can mimic stone without the low yields associated with extraction or can reproduce the effect of clay-based building products without the need for high temperatures in production. Light in weight it is easier to transport and work on site. Fibre-cement is consequently faster to install and less energy intensive in production, saving cost.
Fibre cement is fire resistant
Although there is cellulose (wood fibre) content, because it is held in a matrix of inorganic cement the material has excellent fire-resistant qualities, of vital importance for structures for human occupation. The best combustibility ratings can be achieved with the subtlest of variations to the raw materials. All Cembrit fibre-cement products are non-combustible and classified in accordance with the EN 13501-1 standard.
Cembrit fibre-cement products are resistant to sub-zero temperatures, snow, frosts and thaws, torrential rain, heat, humidity and direct sunlight. They can absorb and release moisture for unlimited cycles without affecting the product’s durability and service life. This makes Cembrit products ideal for external surfaces, particularly single skin constructions.
A defence against rot and humidity
The combination of raw material and matrix structure of fibre-cement also provides excellent durability. Fibre cement is not susceptible to mould or rot damage thereby exceeding the longevity of timber, it contains no metals so will not rust and decay like steel and has low thermal conductivity so will not distort in the presence of heat like PVC. Fibre cement is however porous thereby making it ideal for use in high humidity climates. With such strengths you would think fibre cement should be used everywhere, and you would be right. We have over 80 years of experience of the use of fibre cement across the varied climates of Europe and beyond. There are manufacturers on every continent testament to the popularity and durability of this amazing material. Talk to Cembrit about what fibre cement can do for your project and join the long line of satisfied users of this exceptional building material!
(1) A mixture by weight of 75.5 to 78.5% cement, 16% inert limestone filler, 3.5% cellulose and 2% artificial fibres and process aids. The batch controlled raw materials are mixed in water suspension to form slurry.
(2) Rotating cylindrical sieves collect the solids which are transferred in layers onto a forming roller. The fibres create a matrix onto which the cement adheres. This is the Hatschek process. Water is removed by compression and evaporation.
(3) If required, fixing holes are created in the wet fibre cement sheets immediately before they are (4) transferred to templates which help in the formation of the ”hide” and apply texture if required. The wet material is allowed to cure between the templates for 48 hours in a steady temperature and humidity-controlled environment.
(4) Products are removed from the templates. The cement continues to cure for 10 days, increasing in strength.
(5) Coloured products are sealed on the underside and the edges. The surface is coated with a coloured paint.
The beauty of the Hatschek process is that thin sheets of formable cement are produced, with a high strength to weight ratio, which continue to gain in strength as the cement hydration reaction occurs