Fiber cement

Fiber cement siding (or "fibre cement cladding" in the UK and Australia) is a building material used to cover the exterior of a building in both commercial and domestic applications. Fiber cement is a composite material made of sand, cement and cellulose fibers. Fiber cement board may come pre-painted or pre-stained or can be done so after its installation.

Fiber cement siding has several benefits since it is resistant to termites, does not rot, is impact resistant, and has fireproof properties.

In appearance fiber cement siding most often consists of overlapping horizontal boards, imitating wooden siding, clapboard and imitation shingles. Fiber cement siding is also manufactured in a sheet form and is used not only as cladding but is also commonly used as a soffit / eave lining and as a tile underlay on decks and in bathrooms. Fiber cement siding is not only used as an exterior siding, it can also be utilized as a substitute for timber fascias and bargeboards in high fire areas.

Sheet sizes vary slightly from manufacturer to manufacturer but generally they range between 2400 – 3000 mm in length and 900 –1200mm in width (600 & 450 mm increments). This manufactured size minimizes on-site wastage as residential floor, wall and roof structures lay structural members at 450 or 600 centres.

When used as siding boards, widths between 130mm and 300mm (5.25 inch to 12 inch) are available. Fiber cement thicknesses vary between 4.5-18mm and also vary in density – the lower density resulting in a fibrous rough edge when cut and the higher density having a cleaner smoother edge when cut.

Thermal resistance and sound transmission can vary greatly between fiber cement products. Fiber cement sheet products rate poorly in thermal resistance and sound transmission and separate wall insulation is highly recommended. Generally the thicker and denser the product the better resistance it will have to temperature and sound transmission.

...
Wikipedia