Surveyors undertaking mortgage valuations will be familiar with the ground conditions in the area they cover and will request a coal mining search when necessary to determine if a house is likely to be located over disused colliery workings. We have a long history of coal mining in the UK and many of the old colliery workings are mapped and plotted so most areas at risk of subterranean ground movement can be identified. 

In the more distant past, stretching back thousands of years, there is a history of other types of mining, not so well documented. Even in the suburbs of London – in Pinner surprisingly – there are ancient chalk mines with extensive deep tunnels and galleries. Mining for metals such as lead, copper and tin was long established in areas such as Cornwall well before any attempt would have been made to plot and record the workings for posterity. 

The surveyor’s local knowledge is key to identifying potential risks in these areas and the survey will include not only a careful above-ground inspection of the building for any signs of movement but also a general look at the other structures in the neighbourhood for signs of cracks, leaning walls or distorted door and window openings. 

The household insurance will normally cover structural damage caused by subsidence and this will include the collapse of old mine workings beneath the property as well as the sudden appearance of swallow holes or the opening up of old mine shafts. 

Many years ago, in South Wales, some contractors paid to fill in mine shafts with hardcore used old pit props instead to make a platform within the shaft and then tipped a thin layer of hardcore on top of these to save time and money. In time the timbers rotted and the shafts opened up and collapsed. In my early career I dealt with a claim for one of these where a garden shed had suddenly disappeared overnight with the shed and its contents finishing up in bits inside the old mine workings over 100 feet below. 

In the absence of any means of recovery the shed owner claimed against what was then the National Coal Board for a remarkable number of valuable items said to be in the shed including a motorbike and sidecar. 

Coal mining information for England, Scotland and Wales is held in the national coal mining database maintained by the Coal Authority and access is free of charge. The Coal Authority interactive map viewer allows you to view selected coal mining information on your computer graphically. 

Using this database viewers can find out if a property is affected by coal mining, check if the property being reviewed is in a high-risk area and confirm if there are mine entries on or near the surface such as old mine shafts. 

Additional information regarding other types of mining, disturbed landscapes or made ground can also be found on the Geological Survey Map for the area (including the Pinner Chalk Mines). 

Peter Glover is a surveyor and author of Building Surveys and Buying a House or Flat