Pile Height

The maximum height of the fibres without any straightening out taking place. It is measured from the top of the fibre under its natural in-situ condition to the upper surface of the backing material. This indicates how flattened the surface has become. It can also provide an indication of inadequate infill material, as there is limited support available to each filament, or lack of maintenance work in relation to the amount of usage that has taken place. The terms pile height and pile length are sometimes used interchangeably. Also termed Free Pile Height.