The same lightweight concrete roofing material blamed for safety risks at the Ontario Science Centre is used in hundreds of other aging public buildings across the province, yet officials haven’t pointed to any others that have been ordered closed.
The revelation comes as critics question whether the findings of an engineering report on the science centre’s roof justify the Ford government’s move to close the 55-year-old Toronto facility to the public with less than two hours notice.
Much of the roofing at the Ontario Science Centre is made of reinforced autoclaved aerated concrete (RAAC), a material widely used in the construction of flat-roofed buildings throughout the 1960s and early 1970s.
Although the province has for months been investigating the status of RAAC in Ontario schools and other public-sector facilities, and has identified it in some 400 buildings, all but the science centre remain open, CBC News has found.
An engineering report delivered last week to the province found a small percentage of the centre’s RAAC roof panels have degraded to the extent that they’re at high risk of collapse come winter.
Despite this, the engineers did not specifically recommend immediate closure of the facility. However, the province’s Ministry of Infrastructure urged the Ontario Science Centre board of trustees to shut it down immediately, a move announced Friday afternoon.
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 CBC’s Lorenda Reddekopp reports, the opposition is questioning whether the closure was necessary.
The province began looking at RAAC in public buildings in Ontario last fall, after more than 100 schools in the U.K. were ordered fully or partially closed over safety concerns.
CBC News asked provincial ministries that oversee the largest portfolios of real estate for the number of buildings with RAAC roofing, their state of repair and whether any have been closed because of safety risks.
Top official anticipates no other building closures
Infrastructure Ontario has conducted an initial review of 190 provincial government buildings — such as courthouses and offices — that were built around the province in the era of concern, roughly 1955 to 1975.
That review ruled out the presence of RAAC in more than half, with further investigations in the coming weeks on 79 buildings — 49 of which are currently occupied, said Michael Lindsay, Infrastructure Ontario’s CEO.
None of them have been ordered vacated, and Lindsay said he does not anticipate any will.
“Ultimately we’ll always be guided by the opinion of professional engineers on health and safety,” Lindsay said to reporters on Friday.
“I want to stress that all of the mitigations and monitoring that we’ve put in place for the Ontario Science Centre are also in place for those facilities, so there’s already enhanced management of rainwater and moisture on roofs.”
In addition, about 8 per cent of Ontario’s 4,800 schools have the material, but no school has been ordered closed as a result of RAAC safety concerns, said a Ministry of Education spokesperson.
Last November, the ministry asked every school board in the province to identify all buildings where RAAC has been used and to describe their plans for managing risks, according to a memo obtained by CBC News.
“Boards are required to have an active management strategy in place and can engage specialized professional engineering services,” said the spokesperson.
“Several school boards have been actively managing RAAC through regular inspections, reinforcement of RAAC planks and roof replacements.”
The Ministry of Colleges and Universities did not respond to questions about the number of post-secondary buildings with RAAC, saying only individual schools would know.
Engineering reports find 6 panels at critical risk
The engineering reports submitted to the province by Rimkus Consulting Group assessed the condition of the RAAC roofing panels on the science centre’s three buildings and classed them by risk level, including critical (in need of immediate repair) or high (in need of repair before the next snowfall).
Of the approximately 152,000 square feet of roof area where RAAC panels were used, the engineers found just six panels (each measuring 15 square feet) at critical risk, all of which have been repaired or replaced.
The percentage of RAAC panels found to be at high risk in each of the three buildings were:
- six per cent in the building that serves as the science centre’s main entrance.
- five per cent in the smallest building, with the area known as the Great Hall.
- two per cent in the largest building, home to various exhibit halls.
The summary of the three reports say all high risk panels should be replaced or reinforced by Oct. 31, a project it estimates to cost $522,500.
While the engineers say the buildings are safe for occupancy until then, Lindsay said the closure to the public is necessary so staff can clear out exhibits before any snowfall.
If that work cannot be completed by the deadline, the engineers recommend “restricted access or full closure to prevent any persons from walking in areas where high-risk panels are present.”
CBC News requested an interview with officials from Rimkus Consulting Group but did not receive a reply.
‘You can keep exhibition areas open’
Moriyama Teshima Architects, the firm founded by the Ontario Science Centre’s original architect Raymond Moriyama, says the reports make it “clear” that closing the building is unnecessary.
“Repairs are needed, but on a manageable scale and with potentially minimal impact on the public experience of the building,” the firm said in a statement Tuesday.
The firm is offering its services to oversee the repairs free of charge.
The report also recommends replacing the complete roof assembly in areas with a higher concentration of high-risk panels by Oct. 31, and puts the cost of that at $7.2 million.
Infrastructure Ontario’s Lindsay told reporters that doing such work would require the facility to be vacant.
But Elsa Lam, editor in chief of Canadian Architect magazine, examined the report and compared its map of high-risk panels with the Ontario Science Centre’s layout. She concluded none of the high-risk panels are over key permanent exhibition areas.
“There’s actually no risk to the public or staff if you prevent people from walking under those panels,” Lam said on CBC Radio’s Ontario Morning.
“That suggests to me that according to this report, you can keep all of those key exhibition areas open not only until the fall, but even beyond that, whether or not you spent a penny on repairs of the roof.”
Trevor Hrynyk, an assistant civil and environmental engineering professor at the University of Waterloo who specializes in reinforced concrete structures, says RAAC is about 80 per cent air, making it vulnerable to water penetration.
“If you do have a problem with a RAAC panel, you can’t rely on all the surrounding panels and roof elements to hold it up. So what could be a very localized issue could turn into an actual problem,” Hrynyk said.
Science centre faces costly maintenance work
The roof isn’t the only part of the Ontario Science Centre that needs fixing, according to a business case published last year by the province that cited hundreds of millions of dollars in necessary maintenance work.
The Ford government used that business case as evidence for its plans to shut down the current facility at Don Mills Rd. and Eglinton Ave. and move it to a new, smaller building at Ontario Place as part of the province’s controversial redevelopment plans for the waterfront park.
Ontario’s auditor general cast doubt on the government’s claim that its plan would be a net benefit to taxpayers.
The government had promised to keep the science centre open in its current location until a new facility is built at Ontario Place, scheduled for 2028.
The new centre would be located next to a private spa planned by Therme, the Austrian company awarded a 95-year lease by the province.
The province plans to issue a call for proposals for a temporary location for the Ontario Science Centre’s exhibits in the interim.