Originally Posted by Michael Allen
The top, however , presents a challenge. I would like the "roof" to be conical, consisting of 8 segments (panels) 9" diameter at the bottom, tapering to 1 1/2" diameter at the top. My question is: How do I figure out the proper angle (mitre" ) to cut on the sides of each piece ?
Oops! My bad. I read conical and a cone shaped roof, rather than octagonal, stuck in my mind when I answered.
I just did the roofing on a cupola I built. I laid down one course then marked the cut at the ridges, took the shake to the bandsaw and cut it. Then I did the next course above that until I got to the peak. It works for any roof pitch.
The peak presented another challenge but I was looking at the waterproofing aspect of the installation. I'm not sure the birds care.
Aesthetically, you will probably want to lay ridge shakes on it too. Not sure if you want to put that much detail into it but here's how it's done on human roofs: