Fibre cement

Fibre cement is a composite building and construction material, used mainly in roofing and facade products because of its strength and durability.

Material description

The term "cement" originates from the Latin word "Caementum", which signifies chopped stone. Cement describes a substance, which will react chemically with water and develop into a material hard as stone.

In fibre cement there is a fibre reinforcement, which contributes to making the fibre-cement material even stronger. Together with a carefully planned production process, fibre cement makes it possible to develop strong and long lasting construction materials.^[1]

Today fibre cement is considered as a material physically suited for construction products such as cladding and roofing. It is primarily due to its function, performance and commercial value.^[2]

Fibre cement flat sheet classified, by accredited laboratories, as Category A according to BS EN 12467: 2004 Fibre-cement flat sheets – Product specification and test methods are sheets which are intended for applications where they may be subject to heat, high moisture and severe frost. While the best possible Reaction to Fire Classifications are A1 (construction applications) and A1Fl (flooring applications) respectively, both of which mean "non-combustible" according to EN 13501-1: 2007, as classified by a notified laboratory in Europe, some fibre cement boards only come with Fire Classification of A2 (limited combustibility) or even lower classifications, if they are tested at all.

Material history

Fibre-reinforced cement-products were invented in the late 19th century by the Austrian Ludwig Hatschek. Principally he mixed 90% cement and 10% asbestos fibres with water and ran it through a cardboard machine. Originally, the fibres were of asbestos and the material was commonly used as siding in house buildings due to its low cost, fire-resistance, water tightness, light weight, and other useful properties. After the discovery in the seventies that asbestos is harmful to health and produces lung cancers years after professional or occasional exposition (asbestosis), asbestos use was progressively prohibited and safer fibre alternatives, based on e.g. cellulose fibres were developed in the eighties and applied to secure the widely known strength of fibre cement.

Fibre cement were probably amongst the latest materials on the market to have contained large quantities of asbestos. The reason is that the asbestos fibres are intimately bound to the cement matrix and were first considered to be well immobilized in the cement and less prone to be released in the environment, suspended in the air, and inhaled in the lung than in other materials or applications such as thermal insulation or flocking in which bare asbestos fibres were used. However, asbestos fibres are inevitably released during machining operations of the objects made of fibre-cement and by long-term erosion of the materials exposed to atmospheric weathering and wind when cement degrades. Occupational health concerns and the protection of workers in the fibre-cement factories have finally led to the progressive elimination of asbestos from these products.^[1]

Users of fibre cement boards seeking for high performance and reliable green building materials should source products having been tested by accredited laboratories and proven that they are 100% free from asbestos or other harmful materials such as sepiolite, inorganic fibre or formaldehyde.

Material usage

Fibre cement is a main component of long-lasting building materials. The main application areas are roofing and cladding. The list below gives some common applications.

Internal cladding:

• Wet room applications – tile backer boards
• Fire protection
• Partition walls
• Window sills
• Ceilings and floors

External cladding:

• Flat sheets as base and/or architectural facing
• Flat sheets for e.g. wind shields, wall copings, and soffits
• Corrugated sheets
• Slates as architectural full and partial facing
• Underroof
• Planks

Roofing:

• Slates
• Corrugated sheets

Fibre-cement products have found a wide usage in various sectors of construction: industrial, agricultural, domestic and residential buildings, mainly in roofing and cladding applications, for new constructions and refurbishment projects.

References