A little background: I live in Canada and recently I drove over a crater on a public road (60km max city road), which I assumed was caused by the recent extreme cold weather. It was night time and there were water on the road from melted snow. The crater wasn't big and very visible, but it's deep enough to cause serious damage to one of my tires and I barely made it home.
The next day I went to an auto shop (Canadian Tire for all you Canadians) but they said the damage was beyond repair and I had to replace it for a new one.
I would like to get to the specific of my tire repair before I take it to the dealership. How do I tell if a tire is irreparable, besides the obvious signs such as completely blown holes? And to be more specific, what kinds of tire damage are reparable?