sorry i dont know why they are any different to normal roofs

Thank-you for your answer.

Sorry for necroging this post, but SOS2 has its own roof for ships from what i could find in the files.

if you remove hull, add normal roof (over vacuum of space), add skylight, add hull. it works in that order. not sure if moving the ship breaks it though

It would definitely be cool to get this so we could build a solarium to fulfil the outdoors need. As I understand it the problem is that skylights are very particular about only being built under 'constructed roof', not under any other kind of roof like mountain, solar roofs from Expanded Roofing, or (in this case) ship roofs. Should be pretty simple to fix I'd think, at least so far as allowing them to be built under ship roof. Ideally they'd want to be visible from the outside too, that would be perfect.