Driveways & Groundwork in London

The visible surface of a driveway is the thinnest part of it. Beneath it sits a compacted sub-base of crushed stone that spreads the weight of a vehicle across the ground, and beneath that, the excavated formation. If the excavation is too shallow or the sub-base is not compacted in layers, the surface will settle no matter how well it was laid — usually in ruts where the wheels track.

This is the part of the job that is impossible to inspect once it is finished, and consequently the part most often cut short. A driveway that sinks after two winters almost always failed underneath rather than on top.

Since 2008, planning permission is required in England for a new or replacement driveway over five square metres facing a highway unless the surface is permeable, or unless surface water is directed to a soakaway or permeable area within the property rather than to the road. This is a real constraint, not a technicality, and it shapes the choice of surface.

Falls matter as much as permeability. A patio or driveway should always fall away from the building, and never towards a wall or a doorway. Water directed at a wall finds the damp proof course and goes around it.

Resin-bound surfacing is laid as a trowelled, seamless layer and can be permeable, which helps with the drainage rules. It gives a smooth, continuous finish with no joints for weeds.

Block paving is laid on a screeded bed and jointed with sand. Individual blocks can be lifted and reset, which makes it the easiest surface to repair after service work — an advantage that matters more than it sounds when a water main needs attention.

Tarmac is the most economical over a large area and goes down quickly, but it is laid hot and needs the right conditions and an even sub-base to finish well.