Originally Posted by oh'mike
I would simply screw or nail a 2x4 to the underside of the roof rafters--then tuck the temporary wall in front of it --on the low side---
That is pretty much it.....I had to do something like that when I was merging my old roof with the new roof...
I took a 2x4 and spanned it across about 15' of roof rafters....tacked in a few kickers (2x4 at an angle going from the floor to the 2x4) and started cutting.
Nice thing about doing kickers....you can smack them with a hammer to make 'minor' adjustments to the roof height.
As long as your not walk around on the roof, chances are it will more or less support itself for a short time.