How to Balance a Leaning Bookcase
- 1). Remove all knickknacks from the very top and top two shelves of the bookcase you want to straighten. You're going to be moving the case a lot and you don't want anything falling down on you or breaking.
- 2). Gently push backward on the bookcase. If it's already leaning forward, it should tilt and move with very little pressure. This is what makes leaning bookcases both dangerous and easy to fix.
- 3). Slide the narrow end of a wooden shim under the foot of the bookcase. Continue pushing the shim until its wide end is lined up with the bottom edge of the bookcase.
- 4). Place shims at the right, left and center of the case. This allows for equal weight distribution.
- 5). Place a level across the top of the bookcase. The bubbles should sit in the center of each liquid tube. If the case still tilts forward, add a second shim on top of each existing shim. If the case leans backward, you may pull the shims out a little or leave them alone. A backward-tilting case is very stable.
Source...