I'll start off with words from a different post, since the environment is the same: The roof is the ceiling of my single-story contemporary house (built 1959). The cathedral ceiling is also the roof; there is no attic or space between the inside ceiling and the roof (it isn't a raked ceiling). The ceiling is tongue and groove planks, above which (I presume) is plywood sheathing, to which are attached the shingles (fiberglas, I think). Ceilings are 8' high along outside walls, rising to 12' at the peak. There are no rafters (I said 'joists' previously but 'rafters' is what I mean); the whole thing rests on 5"x15" solid pine beams that run the length of the house (beams are roughly 8' apart horizontally).
This issue is about a skylight: I'd like to add one to a bathroom that has no window. Problem is, I've contact several contractors who install skylights and they figuratively shake their heads. They say they'll get back to me with suggestions/plans but none ever does. I've looked at plans for skylights and they all seem to be made for attic-style roofs or at least for raked roofs, where there is more space between the top of the roof and the ceiling. In my case, I'm guessing that there is probably no more than 3 inches between the top of the roof and the bottom of the ceiling.
I can't imagine that this is a unique problem, so would appreciate ideas and suggestions.