Related question: What is this called (adjustable angle pipe footplate)?
After posting that previous question, I began to think that there's likely both a cheaper, and sturdier way to accomplish what I'm after.
Here's a sketch of the plan. The gray lines represent the garage. The red and blue lines represent a tarp canopy frame that will be built with 1 3/8" chain link fence pipe and steel brackets.
The blue line represents the pipe that I'd like to mount to my roof. It would run horizontally. A simple pipe clamp would likely work, but I'd like to get some space between that blue pipe and the roof to allow some air flow (and water, of course, as it needs to reach the gutter).
Is there some sort of sealable roof flange that would give me 6" or so to work with in height that would allow for a pipe clamp to be bolted to the top of it?
If I had to invent something, this is what I was thinking. Essentially a reinforced angle bracket with mounting holes that can be covered by a shingle and a mounting hole in the air that one could bold a pipe clamp to.