SNN113425 - Kirby Hall, Gretton, North Northamptonshire: Report on Geophysical Survey, July 2021

A Ground Penetrating Radar (GPR) survey was conducted at Kirby Hall, Gretton, North Northamptonshire, to investigate the immediate vicinity of a collapsed flagstone in a small storeroom adjacent to the Great Hall. The collapse occurred following substantial waterlogging of the ground floor of the building over the previous winter and the survey was extended to cover the whole flagstone floor of the Great Hall. Additional GPR coverage was conducted over the South Lawn beyond the building to determine the location and condition of drainage conduits serving the building known from a previous earth resistance survey. The GPR survey was conducted in response to a request from the English Heritage Trust in advance of works to address the flagstone collapse. A combined area of 0.4ha was surveyed with the data from within the storeroom suggesting the voiding in the immediate area of the flagstone collapse is relatively localised. Areas of high amplitude response within the Great Hall may require further invasive investigation to determine whether this remains structurally sound. Results from the South Lawn corroborate the previous earth resistance survey and suggested some additional detail associated with possible structural remains.