A Mining Investigation is required when it is necessary to establish whether there is a risk of subsidence to a property from former mine workings, normally identified by the Mining Search or an adverse Property Inspection.

A Property Inspection is a survey of a dwelling and cursory assessment of adjoining land in order to determine if there are any current signs of structural defects or settlement indicative of mining related subsidence.

The Mining Investigation enables accurate assessment of the risk and, in the event no adverse mining features are found, provides the assurances required. The investigation is supervised by a qualified mining consultant and is designed according to the suspected mining feature/s, the nature of the site and the specific requirements of the client involved. Investigations are by means of excavation and/or drilling.

A Mining Investigation by machine excavation involves the digging of trenches to bedrock in order to expose any suspected shallow mine workings. This particular method of investigation is ideally suited to building plots or large properties where access is unrestricted. The typical duration for a domestic property is one day.

A Mining Investigation by drilling is carried out by a specialist contractor under the supervision of Cornwall Consultants Limited. a highly manoeuvrable percussive mini-rig is used this type of investigation is suited to properties with restricted access, particularly where mine workings are suspected directly beneath existing buildings.

The drilling programme involves a series of vertical and inclined boreholes surrounding a dwelling or can concentrated on an isolated area of subsidence.

The boreholes are a discrete 11cm diameter and surfaces are fully reinstated with turf or concrete.

On completion of drilling, information from the boreholes is interpreted and a full technical report is produced, including plans and borehole sections of the ground conditions. If a mining feature is encountered, its position, extent and associated risk is quantified so a structural engineer can design appropriate remediation.

Cornwall Consultants Limited can also undertake detailed surveys of abandoned mine workings in order to assess their structural integrity and will witness their remediation, carried out by specialist contractors.