I have a 2 car garage with a 16' ceiling yet the usable height is 8' I've been told I can place 2x6 joits higher up, using bolts and plates as well as twist plates between the rafters and top plate, which would allow me to cut out the old joists and enjoy a higher ceiling (excuse my use of wrong terms) will this work? is it safe? to code? how high up can i go? anyone done this and have some tips??? diagrams or drawings? THanks, Guy