The Parc des Saphirs project turned part of a wooded area beside the Royal Québec golf course into a city park. The resulting sports, fitness and family linear park now occupies a former Hydro-Québec easement. It will eventually include a ropes fitness course, strength-training stations, skating tracks, volleyball courts, and a BMX pump track. The main park facilities are an outdoor covered skating rink and service building.
The assignment was to provide a sheltered winter-and-summer space. It has a large roofed-over surface that serves as a skating rink in winter and can be used for dek hockey or basketball in summer.
Putting a structure that size into a natural setting required a great deal of attention by the designers to would fit everything in. The building is set perpendicular to Rue des Saphirs on the edge of the woods. It has a 48-space parking lot for park users with decorative plants. The open end of the rink faces the street to make it more inviting for the public. The few rooms required are at the other end, closing off the playing surface to the northwest to provide shelter from the prevailing winter winds.
What makes the project unique however is the big roof with its wood‑and‑steel hybrid frame.
Architectural and structural concept
The designers wanted the structure to be made of wood as much as possible while creating a sense of lightness. They worked through and assessed many variations, refining the concept to find the best design for the setting. The versatility required from the building led the team to develop a structure able to accommodate both winter and summer sports, while also getting as much out of the service building as possible. The result ended up being the hybrid solution for the covered rink.
The architectural concept is based on the large wood–steel hybrid frame. The glulam structure with its steel tensioning system supports a 28-meter clear span despite being relatively thin. Its geometry also allows for the roof to drain on either side away from the building, facilitating rainwater management. The great wooden shade sail is supported by a steel colonnade of Vs on either side of the playing surface. The steel support system is designed to integrate the wind bracing for the whole roof without the addition of other elements that would interfere with how the structure is read.
The northeast section of the roof also covers the service building where people enter. This free-standing section, the enclosed part of the facility, contains dressing rooms and a multipurpose common room. It also has a garage for rink maintenance equipment as well as an equipment rental counter. The service building is entirely supported by a light wood frame and the cladding is spruce to strengthen its relationship with the main roof.
The biggest innovation in the project is its strategic use of wood. The service building features a light structural frame that works very well for these kinds of spans and should be within many contractors’ budgets. The skating rink cover makes the greatest possible use of glulam with the addition of steel to increase its span while keeping the budget under control. This also lightens everything visually.
The unexpected shape of the roof is a breakthrough in itself. The main variable-inertia trusses are sized to optimize the volume of the wood at every point. Each truss is made up of two identical pieces of wood connected together in such a way as to hide the joints between trusses, tie beams, and columns. One assembly that required dozens of connectors was hidden in a joint between the trusses and columns. The columns are set in Vs and supported halfway between two trusses. Their support point is offset in all directions, which creates a surprising balance.