I have a 24'x24' garage with 6/12 pitch that I am attaching on back end a 16'wx8'd shed/extension, Just wanting to make sure my calculations are correct, my run is actually 7' 11.5" and rise at 6/12 would be 47 3/4" giving me a 26.6 deg angle that I will need to cut each end of rafter to attach to ridge board, my rafter will be right @ 8' 10 3/4" not including my 12" over hang and 3/4" subtraction for ridge board thickness so that would make overall rafter length being 9'10". (Is 12" overhang suffice/standard). Walls are right at 7.5' height
Does all this sound correct so far? And how would I make sure to cut the birds mouth correctly?? And with using 2x6 rafters @ 24" centers I need a 2x8 ridge board correct?.
Ceiling will be open with no joists. I live in Louisville KY and winters are mild for most part snow load is 15 psf. I will be using rafter ties.
Oh and what about wall and roof sheathing I was thinking 7/16 x 9' OSB for wall horizontally because each wall is just an inch or two over 8' like 97" and I didn't want to gap anything or make a 1-2" strip and OSB is only thing that comes longer then 8' and for roof was thinking either 1/2" or 5/8" plywood.
Any thoughts oversight, errors, or corrections I need to make. Thanks