Roman box-flue tiles

Scientific analysis of Roman box-flue tiles from Chichester and Fishbourne Roman Palace

Excavations at Ashtead villa, Surrey have not only revealed various villa buildings but also the remains of two Roman tile kilns. Some of the tiles made at Ashtead were keyed with wooden rollers applied when the clay was still damp, before they were put into the kiln to fire. This keyed was added so the tiles (known as box-flues) could be more firmly mortared into place.

Box-flues are hollow box-like tiles set into walls to allow hot air from an under floor hypocaust to heat the room walls. Six different wooden rollers were used at Ashtead. One of these wooden rollers was also used to key box-flue tiles used in buildings in Chichester and Fishbourne Roman Palace. By analysing the chemical make-up of the clays it should be possible to say whether these came from Ashtead or whether the wooden roller was used at a different tileworks which supplied box-flues to Chichester and Fishbourne. Analysis should also reveal whether the tiles used at Chichester and Fishbourne originated from the same tilery.

Dr Ian Betts
Building Materials Specialist
Museum of London Archaeology