Excavating for your Pool in Bad Ground Conditions

The difficult clay ground conditions in S and SW France

As you know I am a Civil Engineer and and Civil Engineering education teaches students to be very aware of ground conditions wherever they are. As I have spent plenty of time in South and South West France we expected to be building pools mainly in rock and sand and gravel in the river valleys.

What we did not appreciate is how the limestone rock in the South and South West of France weathers into clay that is unimaginably difficult to deal with when it is saturated. We also did not realise that the limestone is predominantly covered by a metre or so of this clay just about everywhere.

Neither did we appreciate that the swelling and shrinkage in this layer is as bad - if not worse - than the swelling and shrinkage in the heavy clay soils that are common in England.

In fact just recently the French government has become increasingly concerned about "La Secheresse". This occurs when a long dry period causes clay shrinkage that is damaging more and more French property.

Ground Water also causes Problems

Ground water levels in the limestone rock also fluctuated much more than we expected and we found that problems with high flows of ground water and springs can occur in the most unexpected places.


UK Ground Conditions

UK ground conditions are generally easier to manage than those in France.

But the level of the ground water varies a lot more - both from season to season and from between different areas.

Because of this we always advise our UK clients to have a low cost

site investigation carried out. We normally manage this on behalf of our Clients.