The skylight we put in the bathroom wasn't too bad at all to do.
Current rafters are 20-22" apart (They vary) so our 15X30" skylight in the bathroom was framed in between 2 existing rafters.
In our stairway that has the roofline directly overhead, a rafter runs down just about the middle of the stairway. We'd like to add a 15X60" skylight here.
So, I thought I could just run 2 new rafters along the sides of the skylight similar to the bad picture below since we have relatively easy access to the roofline from top plate to ridge board.
Yes, the original rafters are a bit undersized by today's standards. Thankfully, the 12/12 slope has kept the snow loads down over the years. We can match the existing rafter size and still have enough strength for today's building code if we use LVL. No problem there.
But what do I do about the fact that there is no opposing rafters on the other side of the ridgeboard to take any load from the rafters? Do I need to add 2 more full rafters to the other side? Do I add 2 more short rafters to the other side that I header off to transfer load to other existing rafters? I don't want to end up w/ this:
My wife and I were just discussing the planning of this skylight last night, and I don't want to tell her we can do it for sure until I know I'm sure we can do it!