The museum, which closed in September after leaks in the roof led to unsafe levels of mould in the air, had communicated its desire for a new roof at its 50-year-old Ottawa location as early as 2010.
In a timeline obtained through the information request, the museum said it told the Department of Canadian Heritage for four consecutive years, beginning with the 2010-2011 corporate plan, about the roof and the funding needed to fix it.
An engineering assessment in 2010 also "revealed that the Museum's roof lifecycle had come to an end and required replacement given the potential for roof failure."
Museum officials met with the department on Dec. 17, 2013, to present four options: patch the roof and maintain the status quo, partially repair the roof, completely replace the roof or build a new, angled roof over the existing one.
The museum's presentation from that day shows a recommendation for a partial replacement (at a cost that's been blacked out) that would take a minimum of 16 to 17 months. A formal request was made to the Risk Management Reserve, and approval was given by Heritage Minister Shelly Glover to get another cost estimate.
A submission to the Treasury Board was in the works for the last week of September when unsafe levels of mould caused the museum to be evacuated and closed Sept. 11.
49 distinct leaks in less than a year
That timeline was part of a package of documents dated Sept. 22, 2014. The documents also included a list of all the leaks in the museum's roof and the areas affected.
"Water leaks all weekend — closet between Connections and Innovations, 4 small leaks in Connections, Innovations, Biocomposite Plastics exhibition, Electrical Panels on south wall, in between walls of Energy and Technozone, Technozone carpets soaked," said the entry for Jan. 10-12, 2014, describing nine of the 49 distinct leaks reported from Thanksgiving weekend 2013 until the closure.
Some of those leaks meant parts of exhibits had to be closed or covered with plastic to protect them, including when the museum was open.
"The cars wrapped in plastic!! Is this a morgue?" one museum visitor said, according to a quote included in a section of the Dec. 17, 2013, presentation.
False start on roof repairs
CBC News previously reported that a roof repair project for the museum was launched in October 2013, with a budget of $3.2 million over five years to remove asphalt, add insulation and re-seal, among other fixes.
The museum's funding request said work was halted immediately after workers found "advanced deterioration of the existing roofing materials and the presence of asbestos in the crumbling cement layer" when they started the project.
Museum CEO Alex Benay and regional minister John Baird were unavailable for comment earlier this week.
Last month Glover announced $80.5 million of funding for upgrades to the museum including a complete roof replacement, upgrading the facade and exhibit space and retrofitting it to better handle earthquakes and fires.
Documents received in the request said a new building has been "contemplated" since the mid-1960s, and funding had been received in 2008 to start planning work on a new museum.
The museum is expected to re-open in 2017.