It is made from septarian nodules that are found is clay outcrops. These photos were taken on the beach at the Isle of Sheppey. During the 1800’s this was one of only a few natural sources of the material known in the UK.
Roman Cement is an incredible product. It is very strong – even stronger than Portland Cement – and is totally waterproof. It was used in the construction of the sewers, docks, large structures required for the railways, bridges etc. as well as for the facades of expensive London terraced houses. Today, it is little known and largely forgotten.