my trusses are 24" apart. I want to make a 48"x48" access ( approx ). My plan was to beef up the bottom part of the trusses on each side, and the middle one that would be cut, have it sitting on 2x4 box screwed in the the adjacent trusses. im in canada, alberta if that helps with anything for regulation and codes. i did a quick rough drawing of what imthinking.