Canada’s 2SLGBTQI+ National Monument:

Pomerleau Leads Construction of "Thunderhead"

^{Photo ©: Public City Architecture}

Pomerleau is working as Construction Manager for the National Capital Commission (the “NCC”) to construct the 2SLGBTQI+ National Monument in Ottawa. The monument, named Thunderhead, is being built to recognize discrimination faced by all 2SLGBTQI+ communities in Canada, including during the LGBT Purge. This Landmark project is being developed and paid for by the LGBT Purge Fund, in collaboration with Canadian Heritage and the NCC. 

Remembering the LGBT Purge: A Space for Truth, Healing, and Renewal

The LGBT Purge refers to a systematic campaign carried out by the Canadian government from the 1950s through the early 1990s where individuals were investigated and often dismissed from positions in the civil service, military or Royal Canadian Mounted Police due to their sexual orientation or gender identity.  The LGBT Purge Fund is a Canadian non-profit organization established in 2018 dedicated to reconciliation and memorialization projects honoring 2SLGBTQI+ individuals who were systematically discriminated against by the federal government between the 1950s and 1990s.

The monument being built is called Thunderhead, to symbolize a dynamic cloud of energy. Thunderhead is a monument illustrating the strength, activism, and renewal of queer communities, rooted in Anishinabe teachings and set to stand on unceded Algonquin territory as a space for collective expression and healing

This monument will sit in a park on the Ottawa side of the Portage Bridge, which connects Ontario and Quebec over the Ottawa River, just west of Parlament Hill.  The area around the monument will feature an orchard, medicinal garden, a healing circle and a path tracing 2SLGBTQI+ history in Canada.  

Scope of Work of this Monument Construction Project

Our scope includes construction and re-alignment of the multi-use pathway, including earthworks, site services and lighting, micropile foundations, landscaping, and erection of the 2SLGBTQI+ National Monument.

Responding to Challenges

Constructing the 2SLGBTQI+ National Monument, Thunderhead, involves a range of complex challenges typical of a high-profile public infrastructure project.  As Construction Manager, Pomerleau must coordinate with multiple stakeholders, including the NCC, Canadian Heritage and the LGBT Purge Fund.  Navigating regulatory approvals, site considerations and public visibility is required.   

Constructing Thunderhead adjacent to the Ottawa River involves several environmental considerations that must be carefully managed throughout construction. To mitigate any concerns about potential runoff or erosion that could impact water quality and aquatic habitats, Pomerleau put robust environmental safeguards, including erosion control, waste management protocols, and careful site planning, into place to mitigate any ecological disruption. 

Health and Safety Considerations Around the Project

The health and safety of the public, our workers and all stakeholders is always top priority.  As a COR-certified company, we are committed to best practices, upholding the highest standards, and fostering a culture where safety is embedded in every aspect of operations.  

For the upcoming placement of the monument (spring 2026), we are using a small mobile crane, and our safety plan includes:  

• Secure fencing, clear signage, and dedicated pedestrian de-tours
• Hoisting safety protocols, including load assessments, weather monitoring and equipment inspections
• Continuous oversight: our on-site safety advisors will monitor all activities  

“This project reflects our unwavering commitment to safety and our proactive team approach to protecting both the public and our team”, states Brent Masson, Project Manager.

Environmental Protection  

The monument site sits adjacent to the Ottawa River. Sediment and environmental management are a priority during construction to mitigate impact on the adjacent environment.   Pomerleau is using a silt fence – geotextile fabric stapled to wooden stakes – placed below grade as a basic but effective deterrent to keep sediment from leaving the site.  
 

Innovative Practices

3D Modeling of the Monument  

A collaborative, model-driven approach will ensure precision in both design and construction execution:  

• The design team initially developed the concept using advanced 3D modelling techniques.  This digital model was then used to produce detailed fabrication drawings
• The monument’s interior shell is composed of Glass Fibre Reinforcement Concrete (GFRC) and steel allowing for intricate forms without the need for traditional rebar reinforcement, enabling lightweight, durable panels  
• Design includes complex design geometry, glass mosaic tiling, and the integration of structure and landscaping

The use of Procore, a construction management software platform, to control project documentation and construction and QA/QC is standard on this project.

Stakeholders of this Construction Project

• LGBT Purge Fund - Customer
• Canadian Heritage - Stakeholder
• National Capital Commission – Client / Stakeholder
• Public City Architecture – Landscape Architect and Architect
• Pomerleau Inc. – Construction Manager 

For more information on this project:  

Thunderhead | Canada's 2SLGBTQI+ National Monument 

Home - Purge LGBT 

The Project in Numbers  

• 48 micropiles
• 30 + light fixtures (landscape and Thunderhead)
• Several hundred meters of sidewalk and granual pathways
• Approx. 1000 cubic meters of concrete slabs and sidewalks
• Thunderhead monument is 10.7 meters tall and apprx. 8 m in diameter with approx. 64 exterior Glass Fiber Reinforced Concrete panels with a max. Size of 45.5 ft2
• Approx. 2045 ft2 of mosaic tile
• Approx. 94 linear meters of quarried Tyndal stone
• Approx. 3700 square meters of sodding