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 *. CBM is always interesting.
Even more interesting were the fragments of Roman CBM from our site at the former Arena Club within the old garrison at Colchester. The Trust conducted an archaeological evaluation at the former Arena Club in May-June 2017. During the evaluation, we uncovered further remains of the Roman circus and recovered a remarkable Roman horse hoof-bone – see our item on this web-site at www.thecolchesterarchaeologist.co.uk/remains-of-the-roman-circus-and-a-remarkable-find/ . The site also produced a significant quantity of Roman CBM (238 fragments). Most of these represent Roman roof-tiles and brick but the assemblage also includes brick and tile, and flue tile, as well as one tiny tessera cube… The Roman CBM was all made in fine-medium sand orange-red fabrics and it was probably all made locally. We date most of this CBM to probably the 2nd-3rd century. The assemblage includes three complete Roman roof-tiles, ie two imbrex and one tegula. It is unusual to find complete Roman roof-tiles so these are very interesting!
The two imbrex tiles were excavated from ditch F59 in Trench 15 and the one tegula tile from feature F79 in Trench 22. The tegula tile is a cutaway form and may date to after the mid 3rd century. It is not flat but slightly curved: it has been suggested that such tiles were manufactured for use in vaulted roofs. Another interesting element of this tegula tile is that the flange was broken off in antiquity above both of the cutaways, so it looks as though it may have been modified to fit into its place on a roof.
This photo. shows ditch F59 in Trench 15.
These three complete tiles suggest new building material which was not used and was discarded, either during the construction or later maintenance of a building, or primary demolition material which had been very carefully retrieved for re-use. They contrast with the fragmentary Roman CBM which we recovered during an evaluation in 2015 on another part of the site at the former Arena Club and which did not include any imbrex tile (CAT Report 843). That assemblage suggests that that fragmentary Roman CBM may have been brought in from elsewhere for re-use here, although the fragmentary CBM from this evaluation may also have been brought in for re-use. Ditch F59 also produced three joining fragments of a tegula tile which, together, include a nail hole: this would have been used to fix the tile, in the lowest row of tegula tiles on the roof, by nailing it on, as these tiles carried the weight of the tiles further up on the roof and were the most vulnerable to slipping (tiles with nail holes are dated to the mid 3rd century and later).
These two photo.s show the two complete imbrex tiles, side by side and then approximately fitted together.
These two images of the three tiles are taken from CAT Report 1142.
The three complete roof-tiles are unusual and very interesting in being complete, but they may be even more interesting – it is possible that they were associated with the Roman circus, the site of which lies across the evaluation site. The tiles may have been used in the roofing of parts of the Roman circus, ie the magistrate’s box above the starting-gates and the temple structure on one long side of the Roman circus. The site at the former Arena Club has produced stone, in the form of demolition material, which derives from the Roman circus. However, these complete roof-tiles may derive from Roman burials in the area. A Roman burial which we excavated in 2000 on the Abbey Field, near this evaluation site, was set within a box or cist built of whole tiles (but these were like flat lydion tiles rather than roof-tiles: CAT Report 138). This evaluation also produced a significant number of fragments of Roman brick, including probable pedalis or lydion tile-like bricks, Roman floor-bricks or spicae, and what may be part of a special brick (cuneatus) for an arched opening. The report for this site is CAT Report 1142.
Roman roofs were constructed using parallel lines of alternating flat tegula and curved imbrex tiles which overlapped (sketch diagram to follow).
The featured image (also at the top of the item) shows Trust excavator Harvey showing off the tegula tile on site.
All the Trust’s fieldwork reports are publiched online at http://cat.essex.ac.uk/ .
* The small assemblage of Roman CBM (27 fragments) from our recent site in Harwich are Roman or probably Roman in date and include Roman brick and tile, combed flue tile, and roof-tile consisting of flanged tegula and imbrex. This mix of CBM types suggests a relatively high-status Roman building, but most if not all of this material was probably brought to the site from elsewhere.