I had one last little step left on the roof access: Priming the fiber cement board.
While reading through the product specifications of the fiber cement board, I noticed the recommendation to paint it with an exterior grade primer after installation to add to its weather resistance.
Easy! I got a gallon of low VOC primer. Not so easy: We, or for that matter Harold our friend, had to wait for a day warm enough to put the primer on. But we got lucky!