That depends on what it is to be made of, how high up it has to go and the size of the roof.
per roof square.
Usually the best way is to simply build a new sloped roof onto the flat roof.
A traditional shingled roof lasts about 10 - 15 years. You can get much more bang for your buck with a corrugated roof. They are much more durable long term
High Treason!!
That depends on the roof, but the snow simply has to exceed the maximum amount the roof was designed to carry.
Those who live in a building with a flat roof have advantages and disadvantages. A flat roof will not cause as many problems with gutters as a sloped roof would. It is also possible to shovel snow right off of the flat roof. However, it is also possible to have too much snow accumulate on this type of roof which can cause a cave-in or sagging. A flat roof may leak more from too much rain. However, in the extreme cold weather, icicles are not much of a problem with a flat roof. Since the water from the snow doesn't drip down as much as on a sloped roof, the icicles don't have a chance to form.
Fiddler on the Roof grossed $80,500,000 in the domestic market.
You need to know how much a cubic foot of snow weighs. It depends on the sort of snow. There is 1500 cu ft of snow on the roof.
How many roofs did the roof plumber do in a year?
it depends the constructor who fix the roof for a townhouse.
Around 35,000 dollars
Without knowing how the roof was constructed and with what dimension of lumber or steel, there is no way to estimate.