Another roof problem: Plans for science and tech museum addition scrapped after design flaw discovered

The designers of the new Canada Science and Technology Museum knew that one job stood out: this time, they had to keep out the rain and snow.
Years of chronic roof leaks doomed the old museum as water and mould crept through the building.
The crumbling roof dropped bits of asbestos on visitors and staff. It dripped water onto artifacts. An evaluation in 2014 warned that a winter with 25 centimetres of snow could even make the roof cave in.
Patch after patch failed to fix it until finally enginee