signinum

signinum

A waterproof construction material consisting of terracotta or tiles that have been broken into minute pieces and then mixed with mortar; sometimes used as flooring.
References in periodicals archive ?
Bede's references to construction in the Roman manner were endorsed by the Jarrow foundation stone, patches of home-made opus signinum on a floor at Wearmouth, a mortar mixer and the 'greatest quantity of window glass of any site in Europe of comparable date' (p.