This is a cat you're dealing with. They are not like other life forms.

Or am I having an aneurism?

He doesn't hang out up there at night because the local racoons claim the roofs around here as their territory. It there a fence or tree near the roof that the kitty uses to get up there? How ever he gets up there, is probably a way for the kitty to get down.

My calico kitty would get on the roof, probably by climbing one of the crape myrtles and jumping onto it, but she couldn't/wouldn't get off the same way. Once my husband climbed up a few times to get her down, she figured out how to climb down it herself.

For a while, we'd only put the ladder up when we saw her up there, then it got to be too much trouble, so we just left it there unless we needed to use it somewhere else. Eventually our entire cat clan was climbing up and down the ladder or taking other routes up and the ladder down. They loved hanging out on the roof and sneering at the birds.

a neighbor's attic through a hole in their roof. Then - she fell through the ceiling of their garage and left a mess on top of their perfectly maintained car. And oh yeah - the people were away for the winter so the house checker let me in to get the cat. A couple days later the owner flew up from San Diego (to NW Washington) to make sure his car was OK.

This cat has gotten me into more trouble but I still think she is great.