Groundworks in Medway
How Soil Type Affects the Foundations Our Groundwork Contractors Use

Do you know what soil lays beneath your Medway land? Whether you have a vacant plot for a new build development or an existing family home that you want to extend, the soil type at hand has a huge impact on the foundations. Put simply, the type of soil you have informs the system our foundation installers use. As time-served groundwork contractors, P Lunn Plant Hire covers every aspect of groundworks, from concrete bases to drainage preparation.

With a trading history stretching back to our establishment in 1988, we have encountered a wide range of soils. Below, we have outlined some of the most common soil types and how our team adapts to them.


Groundwork Contractors Working with All Soil Types


These soils include:

The rocks above have a high load-bearing capacity, making them ideal for supporting the weight of building structures. In many cases, the team at P Lunn Plant Hire only needs to strip back the rock and level it off so the building work can take place.

However, rock is often impervious. As such, it’s not always possible to install soakaways for surface water and rainwater disposal. In addition to concrete bases, our groundworks expertise covers drainage preparation, so we can draw up a solution tailored to the specific needs of your Medway site.


If the chalk at your site isn’t too soft, our foundation installers use systems 450mm wide for a low-rise building. Regardless, the foundation must have a depth below frost action (700mm). In cases where the chalk is soft, our groundwork contractors excavate until it becomes firmer.

Gravel and Sand

Be it compact dry gravel or sand and gravel subsoils, soils in this category are usually sufficient for strip foundations. Generally speaking, 700mm makes for an acceptable depth, but only if the ground has the appropriate load-bearing capacity.

However, if the water table at your Medway site is too high and the gravel becomes submerged, this bearing capacity halves. As such, our foundation installers keep your foundations as high as possible.

A common solution is a reinforced, shallow, wide strip foundation. The groundworks team at P Lunn Plant Hire excels at concrete bases, so we can pour yours out atop your foundations in preparation of the physical build to come.


The initial 900mm to 1,200mm layer of clay soil is prone to movement. This is due to shrinkage and expansion related to moisture content. This means our groundworks specialists must excavate to a depth where moisture levels remain stable.

British Standard 8004 advises foundations with a minimum depth of 1m in clay soil. However, if there are, or were, trees in the vicinity, our groundwork contractors may dig as deep as 3m.


If your Medway site has peat soil, or waterlogged, loose sand, you have especially poor-quality subsoil. In most cases, a reinforced raft foundation will likely make the most effective solution. Sometimes, however, we can strip back the peat to find ground with a suitable load-bearing capacity and a depth of at least 1.5m. In such cases, our foundation installers may be able to use strip foundations.

From concrete bases to foundation installations, and from drainage preparation to general groundworks, you can rely on P Lunn Plant Hire for all your needs.

Call 07718 341 366 to speak with one of our groundwork contractors about your project. Our company covers all groundworks and plant hire services in Medway and Kent.