How to prepare ground for a car park

Plan before the work starts

Decide on the area, the entrance, the space for manoeuvring and the target levels. Check the requirements for your project in the design documents and with the relevant authority. Underground services, existing installations and water run-off have to be taken into account before work starts.

Do not order aggregate based on the area alone, without deciding on the construction. Heavy vehicles may need different solutions from a car park for passenger cars.

Ground and layers

The extent of ground preparation depends on the condition of the ground and on the design. The material and the layers must allow proper construction and compaction. We build sub-bases as a service — road and car park sub-base explains the scope of work in more detail.

An aggregate car park also needs a carefully chosen material. Simply spreading a layer on soft ground will not make it last.

Puddles and the surface

The slopes should match the planned drainage. Hollows and badly shaped ground can hold water even with a good material. The drainage method has to be agreed before the surface is finished.

Block paving, asphalt, concrete and aggregate surfaces all need the right construction. An earthworks offer does not by itself mean that a particular surface can be built — the scope has to be confirmed.

If the car park is sinking

Record where and in what conditions the problem appears. Check whether it relates to the surface, the sub-base, the ground or water. Topping up without finding the cause may only even out the surface for a short time.

Questions about car parks

Can a car park be made of aggregate only?

That can be the intended solution, but the material and the layer structure must suit how the car park is used.

How do I avoid puddles?

You need the right levels and planned drainage, not just a permeable material.

What should I do about ruts?

First check the cause and the extent of the problem. Do not assume that replacing the top layer will be enough.