The grade I listed church of St Mary’s, Tutbury (Staffordshire) was constructed between 1160-1170 and the upper section is believed to be original with lower sections replaced in the nineteenth century. The doorway consists of six order of fine carved sculptures with the first order constructed from 30 alabaster blocks each consisting of three beak heads; one animal or human figure has also been recorded.  Other elements of the doorway are constructed from sandstone.

The doorway is highly significant as it represents the earliest specimen of ornamental carved works in alabaster in England and the only known surviving example used externally in the country.

Our journey with the alabaster archivolt at St Mary’s in Tutbury began back in 2013 when we were commissioned to undertake a survey to inform conservation treatment following concerns over what appeared to be a significant deterioration in its condition.

Detailed assessment of the 30 blocks was undertaken with recording showing thick black crust across significant surface area with areas of scaling resulting in loss of carved detail to some stones; fissures or hairline fractures; granular disintegration; inappropriate past repairs; blistering and areas of small losses.

Alabaster is easily stained but also readily soluble in water, it can be brittle and easily dissolved by acidic solutions so proposals for removing the black crust needed to be carefully considered due to the fragile nature of the material and the damage that leaving this crust could cause to the underlying carving. Our proposals including trials for laser cleaning which were undertaken in 2017. Treatment proposals also included consolidation of the stone and careful repointing with lime based mortars.

Trials for the laser cleaning were intended to reduce the harmful impact the black crust was having on the alabaster rather than to remove it completely. This meant that cleaning levels to each individual carving varied depending on the extent of disintegration.

The stones were cleaned in 2018 with works also including consolidation to areas of friable and extremely soft white crystaline surface areas with trials included the use of nano-lime.

The project was presented by our senior stone conservator at Monument in Monuments Conference in Scotland, 2019.