I wanted some sort of guard rail to block the top bunk person from falling off in the night. So I used 2X1 and cut them at a 25 degree angle on each side. I measured from the bottom of the bunk to the ceiling with them angled, we used 5 pieces. Hopefully the picture can explain this one a bit more. It is easy, just hard to explain. I predrilled the holes and screwed them in with 2 1/2 inch screws. Also, I added a 2X4 to the ceiling to secure the top of these pieces.