There is a phenomenon called ‘Shrinking and Expanding’ when a clay-rich soil shrinks (or dries out) and expands (or swells) due to the moisture available, and it has become one of the leading geologic risks in France (known technically as Retrait-Gonflement des Argiles). As per the NHESS Journal, with climate change producing higher temperatures globally, evaporation and transpiration are creating a lot more dry and shrunken soils; therefore, there is a large amount of volume loss in the structure of clay minerals.
In response to large amounts of rainfall after periods of drought, clay minerals can quickly regain water and create large amounts of swelling, creating differential settlement of the foundation of structures and putting them at structural risk. As per BRGM (French Geological Survey), over 11.2 million individual dwellings are in medium to high-risk zones; this ‘quiet crisis’ is a physical manifestation of climate change, with increasing numbers and intensity of extreme weather events (e.g., drought) turning stable foundation structures into very unstable liabilities affecting 54 per cent of France's single-detached housing stock.
