12/02/2014 11:04 EST | Updated 02/01/2015 05:59 EST

Science and tech museum roof 'officially collapsing,' documents reveal

The roof of the Canada Science and Technology Museum is "officially collapsing" and asbestos could be polluting the air inside, according to documents released to CBC News after an access to information request.

An email sent to Canadian Heritage staff on Sept. 18 by the museum's president and CEO, Alex Benay, says, among other things, that:

- The museum's roof is sagging in two locations and is "now officially collapsing."

- A section of the wall needs to be re-pointed due to years of roof leaks.

- White powder is escaping from the ceiling, forcing anyone inside to "have to operate as though there is now asbestos and mould in the air."

- Three sections of the roof need to be braced over the winter to prevent the roof from collapsing onto artifacts.

- The maximum snow load of the roof has been reduced from 18 inches to about eight to 10 inches.

"The time for bandaid solutions has long gone and has frankly led us to where we all are today," Benay wrote in the email, which included a financial overview of the costs to fix the situation.

Benay's email to the deputy minister, associate deputy minister and director general at Canadian Heritage was sent a week after the museum was evacuated and closed on Sept. 11 due to mould discovered in a south wall.

Mayor Jim Watson said Tuesday he's concerned by the news.

"Obviously these latest revelations are concerning. Public safety has to be number one," Watson said.

2013 roof test confirmed non-friable asbestos in cement, documents say

Another document provided to CBC News, listing background information on the museum, said a roof replacement project was launched in October 2013. It was going to be done in sections over three to five years at a cost of $3.2 million.

But "test results confirmed the presence of non-friable asbestos (tremolite) in the cement on the roof," the documents said. "Work could not proceed without disturbing the cement layer, which was found to [be] water logged and crumbling, [and] the project was halted."

The museum remained open to staff and the public, despite more water leaks and dislodged pieces of corroded metal and "disintegrated cement" falling into the museum, the documents said.

While work was being done on the roof, air quality tests were done each morning before the museum opened. When work was not being done, the tests were done every two days, according to the documents.

Barriers were erected, pails were used to catch water, and plastic sheets were used to cover vulnerable displays and artifacts. A firm was also hired to seal the ceiling in deficient areas, providing a "temporary solution for the winter," spring and summer.

Then, an intense storm hit the museum on Sept. 5, causing more roof leakage and forcing the museum to close some sections. The south wall was opened due to the leaks, was found to contain mould, and was sealed temporarily.

The museum was evacuated and closed on Sept. 11. It is expected to reopen in 2017 at its existing location, after $80.5 million in upgrades.