Reducing the cost of subsidence damage despite global warming: Fid-Bau Portal

Reducing the cost of subsidence damage despite global warming

Page, R.C.J.

Much of the housing stock in the UK is built on shrinkable clay soils, particularly in the south-east of the country. When the moisture content of the clay soils is reduced the clay shrinks causing downward movement. This extraction of moisture from the clay may occur in a number of ways, but the main causes are either prolonged periods of dry weather (a combination of high average temperatures and low average rainfall) or tree roots extracting the moisture from the soil in close proximity to a property. The most extreme cases occur when a combination of the two causes is evident. Over the past few years the UK has seen some of the driest periods of weather on record which has meant that clay soils have not been able to replenish their seasonal moisture loss during the winter months. This has caused an increase in the number of cracks appearing in properties and a rise in the number of subsidence claims made against insurance companies. If climatologists are right about global warming, then subsidence damage has become an endemic hazard of home ownership. Prolonged periods of dry weather will continue to cause serious and very expensive damage to the country’s housing stock. The annual subsidence bill of £300 million can only be reduced by improving education and communication within the construction industry and encouraging house owners to look after their investments more carefully. This paper attempts to identify how the cost of subsidence damage can be reduced despite the changes in climate conditions.