Our home has 2x4 roof trusses spanning 25 ft. spaced 16 in. O.C. Currently, there is limited attic storage on a plywood subfloor on the bottom chords, accessed via a small hatch in a closet. We would like to install a fold-down attic stair with a rough opening size of 25.5 in. x 54 in., with the long dimension perpendicular to the trusses. This would mean cutting the bottom chords of three trusses to frame the opening. Is this possible?