Hello all,
Long time lurker, first time poster. A little background, Im a second generation builder from MS. I've learned a lot, sweated even more and sometimes even made some money! I was taught to cut roofs with a framing square and rafter charts. Its archaic yet efficient but some what limited....so I bought a construction master pro at the lumber yard. My question pertains to the calculated jack length measurements. Following is the way I have figured a simple stick framed 2x hip roof 24"o.c. with a 36' length and a 24' width with a 6/12 pitch.
length-width+thickness of ridge= actual ridge length
36'-24'=12' +1"1/2=12'-1"1/2 ridge length
total span-ridge divided by 2 = adjusted run
24'-1"1/2=23'-10"1/2 divided by 2 = 11'-11"1/4 run
11'-11"1/4 run, 6" pitch, diagonal = 13'-4"3/16 common
H/V = 17'-10"7/8
jack adjustment= 2'-2"13/16
jack rafter 1 length 11'-1"15/16
OK, here's the question. Is that jack length to short or long point? Do I need to subtract 1/2 the 45* thickness of the hip(1"1/16) for this length on each jack to make layout work for 2' o.c. Or do I just cut the thing and drop it in place? the reason i ask is a little "magic" has to be worked on the hip with the calculated measurement, but there is no need in dropping or backing the hip if done correctly also those lengths don't jive with my rafter tables.
I know its long winded, but this is nothing they cover in the manual. I know this also borders on info that framers might not want to give out, but I would love to know. Any help would be great.
Thanks fellas