Although it's not clearly stated in the instructions, you do not have to attach all 12 slats to the bed rails. They are bound together with nylon so they're not going anywhere. Plus the center support bar, which attaches in 3 or 4 places also holds them in position. It's best to screw the slats into the rails in 2 or 3 places on each side--definitely the corners and maybe somewhere in the middle. Using more screws than that actually weakens the bed rails and may cause the lip supporting the slats to split.