In late March 1989 a record of archaeological levels exposed in trench cut at the rear of no. 18 Castle Street was made by Dennis Nebiker. The trenches cut by workmen to form a single storey extension to the premises were remarkable, not for their archaeological content, but for their depth, this being in excess of the proposed height of the future building. Further still, the disturbed nature of the garden deposits and the wet weather conditions prevailing at the time of foundation cutting led to considerable collapse of trench edges which made detailed investigation of the archaeological levels impossible. As a consequence an opportunity to record interesting deposits and features was effectively lost.

Despite these difficulties, a complex sequence of intercutting medieval and post-medieval pits, including two brick-lined soakaways, was noted. Natural brickearth, observed some 1.65 m. below present ground level was capped by a colourful sequence of burnt and unburnt clay floors of total thickness 0.30 m., these associated with a Roman timber building. Roman pottery of first- to third-century date was relatively plentiful in the spoil excavated from the foundation trenches and there can be no doubt that a Roman structure existed here.