I am working on an old house that has a garage that needs some updating. The shared wall with the garage has the old house siding (when presumably there was no attached garage). There is a partial ceiling (50%) that holds attic space. The part that doesn't have attic space has the rafters exposed. I also have crawl space access behind the stairs leading from the garage to the kitchen.
After reading several of the questions and answers in this DIY exchange, it appears I need to: (1) Install 5/8" sheetrock on top of (or in place of) the old siding that is installed in the shared wall. (2) I need to find a fireproof solution to the crawlspace access (or close the access entirely with 5/8" sheetrock) (3) I need to figure out a way to make the ceiling/roof fireproof.
For (3) I was thinking of extending the attic floor to cover 3/4th of the garage. I would build a wall on the edge that I am not extending. I would then install 5/8" sheetrock to the "new" garage ceiling (attic floor) and to the new attic wall. Now, what do I do with: (a) access door to attic? Does it have to be fireproof? Can I build same access door that I see built with pull-down stairs? This access door doesn't seem tightly sealed like some of the answers I have seen suggest it needs to be. (b) what do I do with the exposed rafters in the area i did not extend attic? Do I need to install 5/8" sheetrock like a vaulted ceiling would have?
Depending on the answer to (a), can I use the same technology to fireproof the access to my crawlspace?
Lastly, on the 3 sides of the garage that do not share a wall with the house, can I just install 1/2" drywall? And, any additional considerations regarding insulation of any of the 4 walls?