Tarmac supports historic Cardiff church conservation with lime donation

January 6, 2023

The sensitive repair of an historic and treasured local church in Cardiff has been made possible through the donation of specialist Blue Lias limestone by Tarmac, the UK’s leading sustainable building materials and construction solutions business. 

Built in the 13th century, St Mary’s Church, Caerau, is a Grade II listed building that has suffered collapse and storm damage over recent years.   

A project led by the Society for the Protection of Ancient Buildings (SPAB) has seen the heritage charity working with the local community and volunteers across Wales to sensitively repair the church, in line with good conservation practice.   

As part of a wider project led by Cardiff University and supported by Cadw, work at St Mary’s involved undertaking research to identify materials used in the original construction. Mortar analysis identified Blue Lias limestone as the most compatible material for repair and Tarmac was keen to step in and help out with a donation from its Aberthaw Quarry. 

The work also involved reviving a small, traditional lime kiln at St Fagans National Museum of History, which had not been used for some years, to transform the limestone donated by Tarmac into hydraulic quicklime. This was then mixed with local aggregates to create mortar that was used in the repair, replicating the ancient materials believed to have been used when it was first built.

Stuart Escott, cement plant manager for Tarmac, said: “It’s a privilege to have played a part in the repair of St Mary’s Church, as an ancient building that is well loved in the community.   

“The team who have worked on this project have really gone the extra mile to ensure the repair is completed sympathetically. By donating the Blue Lias limestone Tarmac has been able to support these efforts, using local authentic materials to restore a part of our local history.”  

Matthew Slocombe, SPAB director, added: “We’re extremely grateful to Tarmac who made a significant contribution to this important project.” 

The donation of Blue Lias limestone for the restoration of St Mary’s Church is just one example of the wider heritage work Tarmac has carried out within its local communities, with other projects including the recent restoration of local war memorials and supporting an archaeological project that uncovered significant Roman artefacts.

The SPAB is continuing ongoing, UK-wide research into ancient mortars by burning local stone across the country, including at projects in Kent and the Scottish Islands.