Purbeck Marble

The unique shelly appearance and subtle colour variations of Purbeck Marble made it the foremost decorative stone of the English medieval period. It was used extensively for architectural features, including columns and pillars, string courses and sculpture in high-status buildings such as cathedrals, abbeys and palaces, as well as more sparingly in many other churches.

Over the centuries, layers of now-discoloured waxes and coatings have obscured much of the characteristic splendour of Purbeck Marble, but originally its polished surface would have had an opulence that mimicked true marbles and contrasted with surrounding stonework.

Unfortunately, the composition of Purbeck Marble makes it especially vulnerable to deterioration caused by moisture. This can be a particular problem when it is exposed to external environmental conditions or when it is in sheltered locations, such as cloisters, where there are high levels of condensation. As with all heritage assets, deterioration is often exacerbated by lack of maintenance. In the past, attempts at treatment have tended to be piecemeal and inconsistent, but recently there has been an increased understanding of Purbeck Marble and progress has been made in developing methods to combat its decay.

This technical advice note looks at the many complex issues that affect Purbeck Marble, the causes of decay and past interventions. It provides best practice advice for care and repair of this important stone including surveys. This guidance is intended for architects, surveyors, conservators, other conservation professionals and anyone who is interested in or responsible for the care of buildings that contain elements made of Purbeck Marble. It will aid specifiers and practitioners in making informed decisions about conserving and maintaining this type of stone.