Gravel driveway installation glossary
Plain-English explanations of the terms you will come across.
- Angular gravel
- Stone crushed from larger rock so it has sharp, flat faces. The edges lock together under load, which makes it far more stable for driveways than rounded stone.
- Damp-proof course
- A waterproof layer built into the walls of a house near ground level. Driveways should normally finish at least 150mm below it to avoid damp problems.
- Dropped kerb
- A lowered section of kerb and strengthened footway, also called a vehicle crossover, that lets cars cross the pavement. It needs approval from the local highway authority.
- Fall
- The slight slope built into a driveway so water runs away from buildings. Usually expressed as a ratio, such as 1 in 60, meaning a 1 unit drop over 60 units.
- Geotextile membrane
- A permeable fabric laid under or over the sub-base. It separates stone from soil, lets water drain through and helps stop weeds growing up into the gravel.
- Gravel stabilising grid
- Interlocking plastic cells laid on the sub-base and filled with gravel. The cells stop stones moving sideways, which prevents rutting and migration on slopes and busy drives.
- Haunching
- A wedge of concrete placed behind and against edging or kerbs once they are set. It holds them firmly in line and stops them being pushed over by vehicles.
- MOT Type 1
- A crushed-stone sub-base material graded from about 40mm down to dust, defined in the Specification for Highway Works. The fines help it lock together into a firm, load-bearing layer when compacted.
- Pea shingle
- Small, smooth, rounded gravel, usually dredged or quarried from river and sea beds. Attractive and cheap but rolls easily, so it suits paths and grids rather than loose drives.
- Percolation test
- A test where a hole is dug, filled with water and timed as it drains. The result shows how quickly the ground absorbs water and how large a soakaway must be.
- Plate compactor
- A vibrating machine, also called a wacker plate, used to compact sub-base layers. Proper compaction in layers is essential for a gravel drive that does not sink.
- Self-binding gravel
- A fine, graded gravel such as hoggin that contains clay or fines and compacts into a firm surface. Used for rural paths and drives, but can get muddy in wet weather.
- Soakaway
- An underground pit or crate system that collects surface water and lets it soak slowly into the surrounding ground. Sized using a percolation test of the soil.
- Sub-base
- The compacted layer of crushed stone beneath the gravel that carries the weight of vehicles. Its depth and compaction decide whether a drive stays level or ruts and sinks.
- SuDS
- Sustainable drainage systems: approaches that manage rainwater close to where it falls, for example permeable surfaces and soakaways, rather than piping it straight into sewers.
Last updated 6 November 2026