Hard Porous Pitch Maintenance: 03. Construction

The surface would typically have been either a crowned pitch, which was about 350mm higher in the centre, or one with a slope of about 1:90 to 1:100 across its entire width.

A base layer of a stone raft, typically 150mm depth, would be surmounted by a 25mm layer of ash, which acted as a blinding layer between the stone and the surface hard porous layer, which was typically 38mm-40mm (consolidated) in depth.

When an area was being constructed it was usually laid in 3-m wide bays to allow for a consistent material depth and for effective screeding and firming to take place.

With a hard porous surface being a water-bound surface, this means that moisture was used as a binding agent, helping the angular particles with finer material in between stick together.

Too much water and the surface would be a sticky and wet, prone to compaction if rolled, resulting in a waterlogged pitch, or at least one that drains poorly, with cancelled matches and reduced usage (and income), until additional remedial work was carried out to rectify the problem caused.

Too dry a profile and it could be broken down and crumbled into fines and dust, filtering lower down into the profile and which would clog up the profile and reduce infiltration and percolation of water when it rained or when irrigation was next applied, in addition to creating a poorly bound surface layer which would result in increased loose material.

A well-constructed and maintained surface allowed for adequate run-off for most rain situations (excluding extremes and very heavy downpours), as well as infiltration and percolation of water through its profile.

The material had a good range of angular particles which interlocked and produced a firm surface when moist and appropriately rolled and this would stay bound together.

The design rate for water removal on hard porous pitches was typically 2mm to 3 mm per hour, however, heavy rainfall and run-off from a surrounding area could occasionally cause erosion gulleys to develop on a surface. These would have needed to be repaired as soon as possible to reduce major remedial work being needed.