Citadelle de Québec King’s Bastion restoration project

From: National Defence

Backgrounder

The Government of Canada is committed to revitalizing defence infrastructure and preserving our heritage buildings and structures to ensure they support the evolving needs of a modern military. Since 1920, the Citadelle de Québec has served as the garrison of 2nd Battalion, Royal 22e Régiment. We recognize the significant role Canada’s military has played in the history of our country, and the importance of preserving our military history and heritage for all Canadians. This is why we are investing in the restoration of the King’s Bastion fortification wall at the Citadelle de Québec. Built around 1830, the wall needs a major restoration to reinforce its structure and preserve its masonry.

Restoration work

This restoration project involves repairing the masonry of the King’s Bastion wall. Work includes dismantling the wall’s stone facing, rebuilding the concrete core of the wall, and reconstructing the stone facing.

Restoration work began in June 2018 and is being carried out in three phases over the next three years. The first phase, involving the restoration of the north curtain of the wall and left flank, was completed in spring 2019. The second phase of the project began in spring 2019, and involves the restoration of the left face. The right face, guardhouse and final section of the wall is planned for restoration in 2020-21 (phase three).

This project is part of an overall $30-million investment in masonry repairs to four of the Citadelle’s retaining walls. Masonry repairs have been completed on the three other walls: the Prince of Wales Bastion, the North Ravelin, and Jebb’s Redoubt. Constructed around 1830, these walls are 6 to 9 metres high and several hundred metres long.

Technical and heritage requirements

The general contractor for this project is responsible for ensuring its selected stone meets all of the technical and heritage conservation requirements outlined in the contract. This includes physical standards for absorption, density, compressive strength, and bending strength (modulus of rupture). The stone must also be similar in colour and texture to the damaged stone being replaced.

As per heritage conservation best practices, existing stone will be reused as much as possible. Only damaged and unrepairable stone will be replaced with new stone that has the same physical and visual properties as the original. This will ensure the Citadelle’s heritage character is preserved according to Parks Canada’s Standards & Guidelines for the Conservation of Historic Places in Canada. This is essential to maintaining the Citadelle’s status as part of the Old Québec UNESCO World Heritage site.

Stone selection

While the quarries used to supply the first stones used at the Citadelle are no longer operational today, similar sandstone can still be found in other areas of Quebec and the northeast United States. The general contractor has selected sandstone (both Sillery stone and Bluestone, also known as Pennsylvania Bluestone), that is green in colour and similar to the original stone used to construct the Citadelle walls. Both the Bluestone and Sillery stone have been used in past restoration projects; they meet all standards for colour and texture to ensure the new stone matches the damaged stone being replaced. They also have similar physical properties to the original stone to ensure the performance and durability of the wall. The general contractor has selected Bluestone from New York for most of phase one of the project, and Sillery stone from Quebec for the remainder of phase one, and all of phases two and three.

Quality assurance program

We have a strong quality assurance program in place to ensure all technical and heritage conservation standards are met. An independent, third-party architect was contracted to oversee the development of all specifications for this project, and is monitoring ongoing restoration work. Additionally, both types of stone are tested by three independent expert parties:

  • Samples of the stone are tested by an independent third-party laboratory before being delivered to the worksite.
  • Every stone delivered to the restoration site is inspected visually, and some of the stone is selected and tested by the architect to ensure it matches the original samples provided.
  • Finally, a second independent third-party laboratory tests some of the stone at the restoration site during each phase of construction to ensure it continues to meet all specifications.

As part of this process, about 5% of phase one Bluestone delivered to the restoration site were refused during the visual inspection due to cracks or damage. The rest of the stones were accepted by the architect. Additionally, about 11% of the Sillery stone delivered since January has been refused during visual inspection due to cracks or damage. The remaining sandstone for phase two and three (Sillery stone) will undergo this same rigorous review process as it is delivered to the work site.

Parks Canada has reviewed all of the project’s technical specifications and heritage standards, including those relating to the selected stone. Parks Canada is satisfied with the measures we are taking to protect the Citadelle’s heritage character. We continue to work closely together to ensure that all FHBRO recommendations and conservation best practices are applied throughout the project.

Stone test results

As part of our rigorous quality assurance program, both American bluestone and Quebec Sillery stone was tested by independent third-party experts, and both meet all physical specifications, including those related to visual appearance. As a result, restoration work will continue as planned.

We continue to work closely with Parks Canada’s Federal Heritage Buildings Review Office and the general contractor to ensure all aspects of the King’s Bastion restoration meet the criteria we identified. This project will ensure the Citadelle’s heritage character and our military history and heritage are preserved for future generations.

/Public Release. View in full here.