Making circular sloped roofs

As you can see in the image, I’m having trouble with making seamless sloped roofs for my yurt, is there any way of doing this without using gapfill?

If you want the decal on there it’s going to be an issue since you are dealing with a pretty complex outer shape for an image.
I’m guessing you want to make a cone style of roof. Have you tried looking for hollow cone Meshes in the Toolbox? Either that or something like Blender to make your own Mesh.