Drainage ( the ability to get water swiftly off the playing surface) is the singular most important feature of a natural grass playing surface that will determine its playablility.
Most grass pitches are located on the indigenous clay loams that characterise our trading area in the south east of England (and some have been constructed on the footprint of old buildings where the ground is heavily compacted or on old landfill sites).
Primary drainage - In all these cases a drainage scheme will be required to get the water away from the pitch. This will generally consist of 80mmm diameter perforated pipe installed at 5 to 10 metre intervals across the pitch at a depth of 600mm filled up with 10mm shingle and topped up with rootzone to the surface. These "laterals" will link into a "main" running along the side of the pitch and then away via an inspection chamber into a local water course or purpose built soakaway.
Secondary drainage - This will consist of either 30mm sand slits passing at right angles to the drains at 200mm centres connecting into the gravel of the drain runs or 50mm Lytag bands at 1m centres, again at right angles to the drains, and connecting into the gravel of the drain runs at 250mm depth. Both the sand slits and lytag bands can be filled up to the surface as neither is harmful to players or mowers.
Longevity - With intensive use the secondary drainage with sand is likely to last up to 5 years, with Lytag up to 10 years, and the primary drain runs can last up to 30 years.
Maintenance - All drainage systems take a while to bed in and should be accompanied in the first three years by the application of sports sand to the surface at the rate of 60 tonnes per normal sized pitch. This will assist the water in migrating to the slits and drain runs and should be repeated as often as the budget allows.
As the British weather continues to deliver records in all forms, the above procedure and regular maintenance should allow at least 3 matches on average per week during the playing season.
We have recently carried out major drainage installation works at the following sites amongst others:
♦ Horsham YMCA ♦ Whitstable & Seasalter Golf Club ♦ Hurstpierpoint College ♦ Sevenoaks FC
We have our own experienced maintenance teams who can help you with the following as part of a Maintenance Package or as a one-off maintenance service.