How much of the Ontario Science Centre roof is at risk of collapsing? See for yourself

Questions have swirled for the past week about why the Ontario Science Centre was suddenly and permanently closed on June 21.

The province has said engineering reports it commissioned from Rimkus Consulting Group show the 55-year-old roof could give way to snow and collapse. As a result, the government moved to close the building now, to decommission it by late October.

"This was a warning a health and safety warning and, as a representative of government, I have to take that seriously," Infrastructure Minister Kinga Surma told reporters at a news conference Monday.

But four engineers and architects told CBC News that what's been said about the reports, and what's in the reports, don't match and closing the building could've been avoided.

"There is no immediate danger," said Yasser Korany, a forensic engineer with KSI Engineering, a firm that examines structures that fail.

"There is enough time to really examine the information," Korany said.

Here's a breakdown of what was in the reports that led to the Science Centre's closure and what experts think about the decision to close the building.

What prompted the roof inspection?

Last year, over 100 schools in the U.K. had to fully or partially shut down after safety concerns connected to reinforced autoclaved aerated concrete (RAAC).

That prompted Ontario to review RAAC in its public buildings, as the material was used widely from the mid-1950s to the mid-1970s, according to the Rimkus reports.

RAAC is a lightweight material, but is also weaker and has a shorter lifespan than normal concrete.

"It is prone to a lot of damage," said Sam Adu-Amankwah, an associate professor of civil engineering at Aston University in Birmingham, England. He saidproper maintenance is key when using RAAC.

RAAC has been used in hundreds of other aging public buildings across Ontario, but only the Science Centre has been forced to close.

What did the engineering reports find?

Rimkus inspectors visited the Ontario Science Centre between Dec. 6, 2023, and March 26, 2024, according to its reports.

The engineering reports review the centre's three buildings separately: Building A, where the main entrance is, Building B, which features the Great Hall, and Building C, the largest building with numerous exhibits.

RAAC roofing accounts for between 50 and 70 per cent of the roofs of each building.

Inspectors conducted visual inspections and reviewed the panels from the underside. Roughly a third of RAAC roofing on Buildings A and B weren't inspected, the reports said, because some areas were concealed by hard ceilings.

Inspectors found six panels across the three buildings were at "critical risk" of collapse.They also said between two and six per cent of panels were "high risk" and at an increased riskof collapsing.

The critical panels were either supported or replaced right away. As for the high risk panels, the reportssaid those would be safe only until Oct. 31, because the high-risk panels might not be able to handle snow.

The reports recommend more support or roof panel replacements for the high-risk panels ahead of the winter.

If the work couldn't be done by that date, the reports recommended restricted access or full closure of areas under high-risk panels. Other options included installing temporary shoring or horizontal hoarding.

There's no mention of a full closure in the report.Marc Winters, director of Rimkus,declined an interview.

The Ontario Science Centre's CEO, Paul Kortenaar,and the chair of its board of trustees,John Carmichael,did not respond to interview requests.

How much would repairs cost?

The province has said repairing and eventually replacing allroof panels regardless of their risk level would cost between $22 million and $40 million and would take over two years to complete.

The reports say addressing the high-risk roofing with reinforcements by the end of October would cost at least $522,500 and would take at least three months to complete.

The reports also recommend roof assembly and replacement in areas with a high concentration of high-risk panels by the end of October, which would cost at least $7.2 million.

The rest of the RAAC roofing only requiresregular review every one to three years, costing $267,000 into 2029, according to the reports.

The reports also suggest eventually replacing all RAAC roofingas the panels reach the end of their life expectancy, andlaid out a plan to do so over the next decade, which it estimates would cost $24.7 million.

Some philanthropists, including Adam McNamara,Sabina Vohra-Miller and Craig Miller, have made offers on X, formerly known as Twitter, of up to $1 million to cover the repairs recommended to keep the centre open.

Moriyama Teshima Architects (MTA), the firm founded by the Ontario Science Centre's original architect Raymond Moriyama, also offered its consulting services free of charge in an effort to "leave zero barriers for the province to reverse this decision and pursue a path that will keep this vital resource safely operating for years to come."

"It's the least that we can do," Carol Phillips, a partner at MTA, told CBC News.

WATCH | Ford government defends Ontario Science Centre closure:

Ford government defends Ontario Science Centre closure

2 months ago

Duration 2:25

Ontario's Infrastructure Minister Kinga Surma defended on Monday the province's decision to abruptly close the Ontario Science Centre last week. Surma says the centre's board of directors decided to close the building shortly after the province reviewed an engineering report that identified issues with a number of roof panels. As CBCs Lorenda Reddekopp reports, the opposition is questioning whether the closure was necessary.

The roof panels aren't the only issue, Ash Milton, spokesperson for the Infrastructure Minister, told CBC News in an email.

The full capital investment to address outdated infrastructure in the building would be at least $478 million, Milton said, pointing to a business case released last yearthat said$369 million would go toward deferred maintenance and critical building repairs, while the rest would go toward exhibit and cosmetic upgrades.

What do experts think?

Closing the entire centre is an "overreaction," Korany said. He says he wonders if the provincial government misunderstood the reports' recommendations.

"I find it upsetting," he said, adding that signs for immediate concern, such as excessive cracking and sagging, were not present in the reports.

Structural engineers "design even for failure," Korany said, so "even after [one panel] cracks and technically kind of fails, it's not going to fall off immediately down below." He says the reports should undergo peer review.

Hitesh Doshi, an architecture professor at Toronto Metropolitan University, says a plan to fix the centre up over time would be more valuable than a total shutdown, especially since the report doesn't say how much force the roof panels can still handle.

"Would there be an additional cost to doing that? Yes. Would that be worthwhile? Yes," Doshisaid.

WATCH | 'No immediate danger' at the Ontario Science Centre, says forensic engineer:

'No immediate danger' at the Ontario Science Centre, says forensic engineer

2 months ago

Duration 0:30

Yasser Korany, forensic engineer with KSI Engineering, reviewed the engineering report commissioned by Infrastructure Ontario and says there was no sufficient risk outlined in it to fully and suddenly close the science centre. He argues that with winter five months away, there is ample time to consider other expert opinions before the next snowfall.

Full closure of the building was "absolutely not" needed and "drastic," said Adu-Amankwah, the U.K. civil engineering professor. Giving theprovince the benefit of the doubt, he said, he could see some rationale in the closure, saying the spread of the high-risk roof panels could make repairs and replacement more complicated and could impact operations.

Elsa Lam, editor-in-chief of Canadian Architect magazine, also examined the reports and concluded none of the high-risk panels are over permanent exhibition areas.

"You can keep all of those key exhibition areas open, not only until the fallbut even beyond that, whether or not you spent a penny on repairs of the roof," she told CBC Radio's Ontario Morning.

On Monday, Minister Surma said conclusions that the building is safe enough for use were ill placed.

"The engineers were quite specific when we spoke to them that if we were to do work on the roof, we should replace the roof in its entirety," she said.

Milton said the reports recommend a "single scope of work" that would replace all the RAAC roof panels and mitigate any risk.

Milton saidmoving the Science Centre to Ontario Place will save people money, but thatpublic safety was the main factor.

"We will not waiver from that, nor will we take chances with health and safety," Milton said.

Why do people want the Science Centre open?

Floyd Ruskin, co-chair of Save Ontario's Science Centre, says the museum is a cultural landmark for the city.

"This is part of the crown jewel of northeast Toronto," he said. "It forms part of the fabric of a community and now the Ford government is ripping that part of that fabric out of the community."

WATCH | Group opposed to Ontario Science Centre closure questions timing of move:

Group opposed to Ontario Science Centre closure questions timing of move

2 months ago

Duration 0:55

Floyd Ruskin, co-chair of Save Ontarios Science Centre, says there are many questions about the province's timing shutting down the Ontario Science Centre including the decision to release the information on a Friday afternoon.

By Thursday afternoon, over 58,000 people had signed a letter, organized by Save Ontario's Science Centre, appealing to politicians at all levels of government to dedicate the investments necessary to save the current site.

"We've had responses from all 124 of 124 provincial ridings," Ruskin said.

"People across Ontario from Kenora to Cornwall, from James Bay to Lake Ontario every single person feels this impact of losing the Ontario Science Centre."