Roman-roof-tiles-archaeology, how imbrices and tegulae actually fitted together. roman tiled roofing is often found in large quantities on digs of roman buildings but it is sometimes difficult to imagine what the terracotta fragments looked like when they were all still in situ covering a roman house.. Some basic hints on identifying roman and medieval tiles, and the differences between them., a photo. of the site at the former arena club, showing spoil-heaps beside one of the evaluation trenches. today (10th november), trust pottery specialist steve benfield was working here at the trust hq and roman circus visitor centre on the fragments of roman ceramic building material (cbm) from our recent site at harwich in essex *.