Kerbing is not a necessary addition to an asphalt area, unless vehicles will be driven over the edge of the asphalt regularly. However, many customers choose to add kerbing for a nicer finish.
We only use heavy duty extruded concrete kerbing, the same type you will see on the side of roads, rather than "garden" kerbing.
This type of kerbing is laid by a machine which extrudes wet concrete in the correct profile and then it is touched-up by hand to give a smooth finish. The advantages of extruded concrete kerbing are that curves can easily be laid; it gives a nicer, continuous apperance; and is very strong because it is laid in large continuous pieces.