Opus signinum wall facing constructed in drainage channel. The opus signinum covers the tile floor of the channel, 5832, and lines the bedrock within the cut. It was applied contemporaneously with SUs 5827-31 to waterproof the channel of the sewer within cut 5833. The opus signinum was applied after and covers the edges of the imbrices of SU 5832.
Opus signinum on north wall of cut 5833