The roof the roof the roof is on?

Yes, a gambrel roof is the same as a barn roof. It is similar to a mansard roof, however the mansard roof has "hipped" corners and the gambrel roof does not.Hope that helps!

a weaved valley: you run one shingle at least 6inches past the valley onto the opposite side of the valley from each side all the way up alternating them each time so they overlap like a weave on top...

u lay your shingels level to the hip and cut the excess diagonal off then cover the hip after each side is roofed with a "cap"

That really depends on several different variables including the square footage of the roof itself and the size / type of the tiles being used.Most of the time when buying roofing tiles / shingles it...