How do surveyors check for subsidence?

Chartered surveyors and structural engineers employ a variety of technical methods to investigate potential subsidence, starting with a comprehensive visual inspection of internal plasterwork, exterior brick patterns, and roof alignments. They carefully measure crack widths and install mechanical or digital glass tell-tale gauges across active fissures to monitor whether the gaps are widening over time or responding to seasonal weather fluctuations. Surveyors also utilize specialized equipment such as non-destructive drain cameras to check for hidden underground leaks that could be washing away foundational soil, and they may commission borehole tests or soil sample analysis to determine the precise clay composition, moisture content, and bearing capacity of the ground beneath the structure.