German architecture studio GMP Architekten is part of the team renovating the Olympic Stadium in Montreal. The work includes replacing the membrane roof that has caused problems for decades with a steel deck to protect the building from falling icicles.
GMP Architekten was commissioned in 2018 to carry out the project after the roof had failed several times since the building was completed in the mid-1970s. It was built as a venue for the Summer Olympics and designed by French architect Roger Taillibert.
The Olympic Stadium is the centerpiece of the extensive development of the Olympic Park built for the 1976 Summer Games in Montreal. The development included a fan-shaped velodrome that was later converted into the Montreal Biodome.
GMP Architekten, Schlaich Bergermann & Partner, WSP Global and Transsolar are working as a consortium to repair the roof of the stadium, while other architectural studios, such as Lemay, are also involved in the project.
The stadium’s roof was originally designed with a Kevlar membrane that could be retracted by 26 cables suspended from a large concrete tower that hangs over the building.
However, the complexity of the machinery that retracted the roof meant that the stadium was not fully ready in time for the 1976 Olympics.
Because of these difficulties, as well as costs, union strikes and more, the project was never fully realized, and the city struggled to produce an efficient, long-lasting roof – much to the chagrin of locals and the wider construction community. Local politicians even considered tearing it down.
GMP Architekten director Martin Glass, who worked on the simple roof design, told Dezeen that the “conceptual” nature of the platform made the project difficult to build at the time.
“This building was a vision that in some ways was a burden to the Canadian construction industry back in the early ’70s,” Glass said.
The team is renovating the roof, replacing the permanent Kevlar membrane while maintaining the iconic tower aspect.
This involved replacing the former retractable roof with a steel cap loaded with a skylight ring and a new outer steel structural ring. 26 wires are used to set up this internal structure.
The cables will hold up 90 percent of the roof.
“When the first tower was built 50 years ago, it was actually designed to carry very high loads, and there was a lot of research and testing done over the last 10 years on the tower, so we know it’s structurally sound,” Glass told Dezeen. “So, we’re able to put most of the roof loads on the tower.”
Glass told Dezeen that replacing the heavy outer concrete ring with a lighter steel and aluminum ring made the suspension possible, as “removing the old ring [them] more weight reserve”.
Currently the team is about 35 percent through the inner part of the roof, which is built under the stadium.
After its completion, “mega cranes” will push the piece up. The cables will then be connected, the gap between the outer ring and the inner roof will be covered by skylights.
When the roof is fully completed, we will have these mega cranes that will push the entire roof up to its height of about 50 to 60 meters,” said Glass. Then the final step will be that the gap between the inner roof and the outer roof will get a big ring of hollow glass.”
The final roof will be covered in white metal, compared to the infamous membrane covering the stadium.
The durable membrane developed in the 1980s was often damaged by icicles that formed on the ropes during the cold Montreal winters, falling and puncturing the delicate fabric.
This situation and the bad weather forced the stadium to be closed for the winter.
“The current roof has almost 20,000 holes,” said Glass. “At some point, it’s a little dangerous”.
“That’s why we don’t go with a membrane roof, but with a metal deck with a special installation of high-impact insulation materials that absorb shocks above the original metal deck – to make sure that nothing can actually penetrate the roof.”
“That will allow the customer to use the field all year round, because you can imagine as an operator, it’s a financial disaster to have a field that you can’t fully operate in the winter.”
Glass expects the interior roof to be completed by the end of this year. Another project, which includes the modernization of the interior, was announced by Quebec’s tourism department on July 17.
Other updates, including the renovation of tourist attractions such as the renovation of the original cable car that runs up the concrete tower and the renovation of the glass observation deck, were announced in 2020.
The final roof will have a light basement, and Glass said the skylight will allow the stadium to receive natural light for the first time.
“Although the membrane is something that can be made transparent, the original interior was completely dark, and there was no communication with the outside because,” said Glass. “For whatever reason, back in the ’80s and later in the ’90s when they were redoing the roof, they chose translucent membrane.”
“With the translucent ring that we are adding to the project, we will know the natural daylight in the stadium. And actually, for the first time, you will feel whether it is day or night, whether the sun is shining or it is raining.”
All in all, the team wants to stay as close to the original design as possible, due to complimenting the project’s structural intelligence and unique spaces, such as the “graduate hall” – a room facing the top of the tower that contains the cable connectors.
“It’s a landmark, and at least from a European perspective of Canadian architecture, it’s actually the most iconic building in Canada,” he said.
“It gets crazier the deeper you look, because they must have had a lot of freedom back in 1976, when they did the first job. There are so many gaps in this field that we’re still amazed to see what they did with it and the opportunities they had.”
He also said that the community’s attachment to the existing project is what makes it possible to choose.
“Therethere isindeedaa lotofpeoplethatthere isa lotemotionallyattachmenttoiexistingprojectagaintoiexistingroof,” said Glass.
“Wehe didnotsearchtodoanything elsethatindeedsticksoutside.Thisstructureis somethingit is already very strong, with its organic quality and vividness of images. Whe understoodthatinewthe roofit shouldactuallytrytoretreat aslowlyagainnotbeanother oneyou are crazyattraction,butbesomethingthatsupportiliving thingsforms,ithe originalshapeagainithe originalon purpose.”
Photo by Patrick Beaudry of Snape Photo unless otherwise noted.
Future Stadium
This article is part of Future Stadium, our series exploring the growing role of monumental sports buildings in architecture and urbanism around the world.