What materials can be classed as permeable?
The most commonly encountered permeable pavings and surfacings are, in no particular order: • concrete block permeable paving (CBPP) • permeable asphalt/macadam • gravel (loose or reinforced) There are permeable or porous versions of many pavings and surfacings, such as porous resin bound surfacing and permeable stone setts. There are even permeable concretes, but these are not really suitable for residential driveways. Standard flag paving, whether it is natural stone or concrete, is tricky to install as a permeable surface, but it can still be laid as an impermeable surface and drained to a soakaway or rain-garden.
