Japanese Style Roof

I have created a lovely Japanese home build and the roof is driving me insane.
Is there any tips on how to do the curved prim roof?
I know it's a vague question but I just can't seem to find the words.
Any help would be greatly appreciated.

try altering a cylinder. half a cylinder flipped around is what you want, unless you want less of a curve and you can try it with a few flat cubes. make them long, thin and flat, and use them to build the curve to your liking. the more you use, the smoother the curve will be.

I use pieces of a cut, hollowed, and flattened cylander, with the hollowed side up, for my Japanese rooftops. This works fairly well for a single peaked, V-shaped roof, with flat triangular ends.

Pratyeka Muromachi makes (and sells) beautiful Japanese builds with very well made roofs. You should check out Pratyeka's profile and see how they are made.

thank you everyone who helped me with this task.
Now I have another problem with filling the corners.
Any ideas?

You might try rezzing a sphere, hollowing it, cutting it in half and dimpling it down to a quarter. Then flip it upside down and fit it, point first, into the corner space. You might have to play with the dimensions to make it fit. I did this to make a corner on a curving-down roof, and it worked just fine.