Everything You Need To Know About Clay Soil Foundations

The construction of a home, office block or community building is a complex process that demands a wide range of machinery and equipment to get the job done right. Everything from the foundations to the roof tiles needs to be expertly installed to ensure the longevity and durability of the structure.

But what happens if your building site consists of clay heavy soil? Clay is a natural soil type containing clay minerals, where this material tends to develop plasticity when combined with water. Read on to find out about the various risks and complications involved with building on clay.


Clay is known for being highly absorbent, where it tends to retain water and cause problems for site drainage. This is because it is made up of lots of small, dense particles which become compacted easily.

Expanding & Contracting

Due to clay’s absorbent nature, it is also liable to expand and contract depending on its water content. Dry clay will shrink, whilst waterlogged soil will swell. Nearby trees can influence the changing water content of the clay, where removing large swathes of vegetation could result in flooding and ground collapse.


Clay is also vulnerable to soil erosion which can further complicate building efforts. Its poor drainage qualities allow the soil to become waterlogged, which can contribute to landslides, flooding and instability.


In construction, piling or deep foundations are ideal for creating a solid base for a building project if you’re dealing with clay. This technique involves the drilling of solid piles into the ground, which help to transfer the weight of the structure throughout the soft soil.

Below Ground: Meeting All You PIle Foundation Needs

At Below Ground, we specialise in commercial and domestic piling and underpinning, where we can also install sheet piles and ground beams in Bristol, Exeter and London.

Contact us today to find out more about our high quality services.