I am in the middle of a reno where I am moving my kitchen to the back of our house. In the process, I realized I would have to more-or-less gut the interior, this after having to replace a section of rotten exterior. The house was built in 1902 and whoever built this extension simply "hung" the new section off the old section with not a whole lot of consideration for the condition the old section was in. When I removed the ceiling drywall and insulation, what I found was, to put it mildly, a "hack" job. Now, I'm not a professional bulder by any means ... just a DIY'er but even I can tell this sucks. So now I am faced with either replacing the entire roof so I can properly replace the ceiling rafters or, maybe, just maybe, find a way to replace the rafters one-by-one from the inside. I think this second option, while not being the easiest perhaps, could work but with some problems, one of which is how to attach the new rafters to the ceiling. Perhaps brackets of some kind might work but the ceiling deck is at most, 5/8" thick so securing this would be a problem.
As far as I can tell, here is a description of what I currently have: 2X4 dressed rafters mixed with older full size 2X4. Rafters are randomlly spaced anywhere from about 30" to maybe 20". The "ledger board is a 2X4 with a weird sort of spacer added in, as you will see in the picture. Some of the rafters do not actually have the ceiling resting on them but some 2X4 spacers have been added here and there. Where the rafters meet the wall sill plate, they have carved out notches to make it fit of the joists and sill plate. Sistered joists, where used, do not span the entire ceiling. A mess.
I know tearing of the roof and replacing all the rafters would be best but as it is almost winter, and I am working by myself, that solution would most likely have to wait until the spring. If there is a way to move forward sooner, I would like to at least look at an alternative solution. One other thing I should mention is that I want to create a "cathederal" type ceiling here so will need to add in perhaps 2X8 joists?
Thanks for your time.