Medieval tile wasters, the misshapen, cracked, or otherwise failed tiles discarded during firing, were recovered from the north-western corner of the cathedral graveyard, and their presence points strongly to a tile kiln once operating at or very near this spot. A tile kiln was a specialised structure used to fire decorative and functional floor tiles at high temperatures; wasters are the inevitable by-product of that process, typically dumped close to where they were made, which is precisely what makes them so useful as locational evidence.

The finds were documented in sources dating to 1866 and 1875, suggesting the fragments came to scholarly attention during a period of considerable antiquarian interest in the cathedral and its surroundings. St Canice's is one of the oldest Gothic cathedrals in Ireland, and the decorative tiled floors associated with high-status medieval ecclesiastical buildings were often produced locally rather than imported. The wasters discovered here suggest that at some point in the medieval period, craftsmen were manufacturing tiles within the cathedral precinct itself, supplying what would have been a significant and technically demanding element of the building's interior.