If you are in the process of landscaping your property and laying down a new pavement or driveway, you may find that soon after the paving has been put into position, it begins to move, causing the surface to become cracked and uneven. This can increase the chance that the paving will be adversely affected by the weather and also creates a trip hazard. The most likely cause of this issue is unstable soil. Below is a guide to everything you need to know about this problem and how you can overcome it.

What is unstable soil?

Unstable soil typically contains too much moisture or consist of a very fine material such as sand. The weight of the paving generates pressure which causes the moist or sandy ground to move underneath it. As the ground moves so does the section of paving above it. 

How can you deal with unstable soil?


The most common way of dealing with unstable soil is a process called soil stabilisation. This process involves the use of special tools, so it should only be carried out by a professional paving company. The contractor will lift any paving which is already in place to uncover the ground beneath. They will then use a special tool to bore into the ground so they can remove a core of earth. This core of earth will allow the contractor to assess the type of ground which lies at different depths beneath the paving. The paving contractor will then inject a solution of wet concrete and lime into the ground. As this solution hardens, it will push out any moisture from the soil and fix it in place, forming a perfect foundation for your paving. In some cases, where the soil is particularly sandy, the contractor may also place a layer of rocks on top of the stabilised ground to further aid its stability. Once this job is complete, the contractor will lay the paving.


If the ground contains very high levels of moisture, the contractor may also recommend that drainage channels be built into the ground, so that any rainwater which falls onto it will naturally drain away. The depth and position of these channels will depend on the topography of the land, so it is best to leave this work to a professional.

If you would like to find out more, you contact a paving contractor in your area.