In this episode of we explore one of the most common but often misunderstood issues in London housing, the effect of shrink–swell clay soils on Victorian terraces.

Through the example of a typical two-storey mid-terrace, we explain how much such a house really weighs, whether clay can “lift” a building, and where the real danger lies. We discuss seasonal shrinkage, tree roots, shallow foundations, and why one house may crack while its neighbour remains unaffected.

With clear analogies and references to scientific guidance, this episode demystifies the phenomenon of clay movement and makes sense of what surveyors see on the ground, movements measured in millimetres but with consequences felt in everyday living.