Guildhall, York

The Challenge

The ambitious and challenging £21.7m project to refurbish and remodel York’s 15th-century Guildhall and adjoining building required heritage building materials that would complement the existing structure. The Guildhall complex is owned by City of York Council and is made up of Grade I, II* and II listed buildings built around a large 15th Century Guild Hall. The building had suffered significant bomb damage during the second world war and received only reactive repairs since it was reopened in the 1960s, putting the building’s future at risk. The aim was to restore the main hall for public tours and civic space and add a new adjoining building to create a new base for York Science Park, to support start-up businesses and provide flexible working and event space and café facilities. Although the new-build element was a modern design, a traditional brick finish had been chosen by the architect and a mortar was needed that would complement this.

Our Solution

After discussions with the Specialist Products team at Tarmac, the client chose Limelite Heritage Lime Mortar, a limebased cement free mortar in a Light Brown. As well as matching the visual aesthetic, the flexibility of Limelite Heritage Lime Mortars allow for slight movement and thermal expansion throughout the life of the building and reduce the risk of cracking. They can also reduce the need for expansion joints to improve the final appearance and along with the ready-to use pre blended formula, reduce build time for the contractor. Lime mortars are also breathable, allowing moisture to naturally evaporate and reducing the risk of trapped moisture and mould growth. This would also help the long-term performance of the building on this naturally humid river-side location.

Results and Benefits

The client was delighted with the finish achieved by the brick laying contractor and the project won significant acclaim from the restoration community. As well as meeting the client’s aesthetic and performance requirements, choosing Limelite Heritage Lime Mortars also helped make the project more sustainable. Lime is produced at a far lower temperature than cement, requiring significantly less energy to produce. Lime also has a unique ability to absorb carbon dioxide from the atmosphere, further minimising long term CO₂ emissions. Like all Tarmac products, Limelite Heritage mortars are manufactured in the UK and certified under BES 6001 Responsible sourcing. Tarmac was the first company within the cement and lime sectors to be awarded the BES6001 ‘Excellent’ rating across its entire product range.

The client and contractor were delighted with the results: “The project was logistically a nightmare as all materials had to be stored off-site and then brought across the River Ouse by barge to the construction site. Tarmac Limelite offered the perfect solution in supplying the lime mortar on pallets premixed in 25kg bags, we were able to transfer from barge by tower crane directly into location required. Quality premixed product helped achieve high end results.” Dean Roe - Phoenix Brickwork.