20mm gravel is usually a 10-20mm graded material. Our "local" material is flint based but it comes in many different colours. 20mm Gravel can be used for: drainage, pipe bedding, planters, grass alternative, driveways and footpaths. 20mm Gravel is a mixture of materials and this depends on whereabouts in the country you are working. It can be any of the following: Flint, Limestone, Granite, Basalt, Quartz or Oolitic Limestone. We deliver small and large loads to Thatcham, Newbury, Reading and all the surrounding towns and villages around Berkshire, North Hampshire and Southern Oxfordshire. To get a quote please call: Thatcham 01635 865679 or Newbury 01635 40009