Historic Building Restoration at Leeds Castle, Kent – NATCEM® 35

Project: Historic Building Restoration at Leeds Castle, Kent – NATCEM® 35

Location: Leeds Castle, Kent

Products: NATCEM® 35.

Contractor: Paye Stonework & Restoration Ltd.

Sub-Contractor: KEW Diving Services 

Client: Leeds Castle

Distributor: EPMS Supplies Ltd

Project Background

Leeds Castle, a historic landmark in Kent, encountered a structural challenge when workers discovered voids beneath the waterline of its moat bridge. The fallen stones created voids that threatened the bridge’s stability. To address this, Paye Stonework and Restoration stepped in to offer a solution. 

To fill the voids, Paye selected NATCEM® 35, our fast-setting underwater mortar. NATCEM® 35 stood out for its proven effectiveness in similar conditions, ensuring reliable results both above as well as underwater. Its use in this historic building restoration provided an immediate, efficient solution, helping to preserve the integrity of the bridge.

The Methodology, for Historic Building Restoration

To restore the historic structure of Leeds Castle’s moat bridge, Paye specifically chose NATCEM® 35 for underwater repairs to fill the voids below the waterline in the landward abutment. This method, of course, followed a series of trials, which not only confirmed the product’s effectiveness but also validated its suitability for the task at hand. These trials involved the team constructing a rough masonry wall using reclaimed stones that had been submerged for several months. They purposely left a gap to replicate the voids expected in the abutment. Then, they submerged the wall with water using a hosepipe, effectively simulating the conditions at the moat bridge.

Next, the team mixed NATCEM® 35 according to the manufacturer’s instructions and promptly applied it to the repairs. Seeing the suitability of NATCEM® 35 in this trial environment, it was decided it would be used at Leeds Castle itself. Divers placed the mortar into the voids at Leeds Castle, carefully compressing it to ensure a secure and lasting bond. Thanks to its fast-setting properties, NATCEM® 35 not only cured underwater but also provided a stable repair, contributing to the long-term restoration of the historic building.