When is an edge restraint needed for paving or paths?
An edge restraint, also known as edging or kerbing, laterally contains paths and paved areas. It is particularly needed where block paving or slabs are laid on an unbound sub-base.
It forms a lateral abutment and absorbs horizontal forces from pedestrian and vehicle traffic, as well as movement caused by temperature changes. This keeps the outer blocks or slabs in position, prevents the surface from spreading sideways and helps joints remain closed. Edge units are less likely to tip or move. Lateral restraint is required for block paving and for slabs connected with connectors on an unbound sub-base.
An edge restraint is not always structurally necessary where the surface is already permanently contained by adjoining load-bearing elements, such as a concrete slab, wall or solid building edge. It can still provide a clear separation between a path, lawn, planting bed or sand area. Common applications include bed edging and marking the boundary of a beach volleyball court.
Set the edging upright in a concrete foundation with a concrete haunch at the back. At least about 65% of its height should be below finished ground level to improve resistance to tipping and movement. A load-bearing, well-drained and frost-resistant base also contributes to a durable edge. Elastic rubber granulate edging can be installed in straight lines and curves.