Most artificial hockey pitches use a sand-dressed carpet with an 18-23mm pile height and sufficient sand infill to keep the fibres upright (60-80% of the pile height).
In general, the denser the yarn the higher the quality of the carpet (more stable and longer lasting) and manufacturers are continuously experimenting with different combinations of curled and straight yarns to further improve the playing characteristics of their turf.
Hockey surfaces are commonly laid onto a 15mm in-situ shockpad over an engineered (tarmac) stabilising base layer which sits on a free-draining stone sub-base
Optional hockey surfaces:
Sand-filled: a low density carpet, 18-23mm pile height, with sand infill to just below the pile for stability
3G surface: Where hockey is the secondary sport or part of a multi-sport requirement, the game can be played on a 3G surface with a pile height of no more than 40mm. 40mm 3G surfaces are infilled with a sand and rubber mix to meet the shock absorbency requirements for football but the playing characteristics will be adequate for school and recreational hockey.
Water-based: a very high density carpet with no infill which requires irrigation via a sprinkler system to maintain a layer of water on the pitch. Although water-based surfaces are widely regarded as giving the best playing characteristics, manufacturers are developing excellent sand-based carpets with hydroscopic (water-retaining) properties which mimic water-based play and are less costly to install.