Sally writes: One of the striking discoveries is how much Roman tile we have been unearthing, especially at Trench A. Much of this is for a Roman heating system for the villa, where hollow ‘box flue’ tiles were used to conduct hot air around rooms in a form of central heating. The patterning on these tiles is pleasing to the eye, but it is not there for architectural aesthetic reasons. The patterns are the keying, which makes the mortar adhere effectively to the otherwise smooth clay surface. Different keying patterns might be attributable to different tile suppliers, therefore a preliminary analysis of the patterning on some of the tiles was made. The patterned tiles from the Day 6 finds trays (contexts 1003 and 1005) were selected and photographed on a smartphone. The photographic background was the wooden floorboards of the pavilion. A standard 4″ trowel was used as a scale. A preliminary visual classification and naming system was devised, according to which the below photographs were classified:
