Between 1900 and the early 1950s (mid 1960s in certain areas) many properties in Cornwall and parts of Devon were built with concrete constructed of poor quality aggregate from mining waste.
This aggregate was readily available at a minimal cost from the waste tips of old mines throughout the South West.
Unfortunately it has now been established that the minerals contained in the aggregate material can cause a chemical reaction which results in deterioration of the strength and composition of the concrete.
Not all buildings of that era are suspect. Many of the concrete blocks were made from good quality materials such as the course waste product from china clay workings, but as a result mortgage lenders now insist that properties built of mass concrete or block construction are tested if constructed prior to or around the early/mid 1950’s.
Inspections are carried out in accordance with the Royal Institution of Chartered Surveyors Guidelines (amended 1997) in order to ascertain that the property is not structurally affected by concrete degradation.