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Bridgewater Monument conservation works at Ashridge Estate

Summer view of the Bridgewater Monument at Ashridge Estate, Hertfordshire.
This summer, a team of specialist conservation cleaners and stone masons will be working to repair and clean the historic Bridgewater Monument. | © National Trust Images/John Millar

The Bridgewater Monument at the National Trust’s Ashridge Estate is undergoing significant repair and cleaning works to both the internal and external aspects of the building this summer.

July 2024

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The Monument will be closed for the duration of the works, reopening Spring 2025.

History and significance

The Bridgewater Monument commands a striking position overlooking the area and is the recognisable feature of most visits to Ashridge Estate, serving as a reminder of the Estate's historical significance during the late 18th century.

In 1604, Thomas Egerton, chancellor to Elizabeth I, bought Ashridge Estate. It stayed in the family and was home to the Dukes and Earls of Bridgewater for 245 years. Francis Egerton, 3rd Duke of Bridgewater, consolidated the family fortune by developing the first canal in Britain, Bridgewater Canal, in 1761. This would revolutionise transport and earn Francis the title of 'father of British inland navigation.'

In 1831-32, his cousin, John William Edgerton, commissioned the eminent architect, Sir Jeffry Wyatville, to build the Bridgewater Monument in his memory, celebrating his contribution to the development of canals in Britain. It is built in the Neoclassical style and holds a Grade II* listing.

The National Trust took over the care of Ashridge in 1926, allowing public access to the Monument for the first time. Today, approximately 15,000 visitors climb its 172 steps every year to reach its viewing platform, with far reaching views to Wembley Stadium and Canary Wharf.

In 2022, a survey of the Monument revealed wear to the stone steps and erosion of the mortar and historic brickwork. We are passionate and determined to protect and preserve the history and heritage of Ashridge Estate to secure its long-term future, and are therefore working with a team of specialist conservation cleaners and stone masons to carry out the necessary repairs and cleaning.

What work does it need?

Sitting exposed to the elements on a hilltop means that over the years we are seeing areas of erosion and a build-up of moss and algae. Welcoming so many visitors each year has resulted in wear and tear, especially the soft York stone steps and external joinery.

Repairs were last carried out in 1996, but it is thought that this is the first time it has ever been cleaned. Built out of Cornish granite, which is particularly light, the transformation will be spectacular and will give visitors the chance to appreciate the Monument as originally intended.

What work is being done?

Working alongside conservation and heritage experts, we are repairing and cleaning the external and internal granite, limestone, and metal to ensure survival of the Monument for years to come.

The external granite will see removal of biological growth, removal of loose mortar, and repointing. The exterior will be steam cleaned for the first time in its history.

Internally, existing cement will be raked out and repointed. Salts on the internal face of the stonework will be gently rubbed down and the area will be cleaned using a poultice. The softer limestone stairs will be repaired using mortar infill.

Metal work will be rubbed down, have rust removed, corrosion treated, and redecorated.

Who are you working with?

We are working with PAYE, specialists in stonework and historic conservation, and Purcell, architects and heritage experts. All methods they are using are conservation approved and have been carefully tested.

The work has been made possible by supporters of the National Trust.

How long will the Monument be closed for?

The Monument is expected to re-open for spring 2025.

As the work progresses, regular updates will be posted here and across our social channels. We hope that you are excited to come on this transformation journey with us, and will support our efforts to preserve Bridgewater Monument for generations to come.

Conservation in action

24 June

The beginning

On 23 June, the Monument welcomed its last visitors before repair works begin on 24 June.

To kick off the project, 27 metre-high scaffolding will be erected over the next 6 weeks. 

Project FAQs

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