Lifts on Floor

• If you need to raise only one or two legs on a bed frame to make the frame even on an uneven floor, you can use bed frame risers or rubber wedges on that side or end of the bed. If you prefer not to buy risers or wedges specifically for the frame, use household items like small wood blocks or folded cardboard to elevate the legs.
  
  

Shims on Frame

• You don’t have to build up a bed frame from beneath to even it up on an uneven surface. If you want to level up just the sleeping area of the bed, do so by adding shims or extra cross rails on a bed frame. Shims added down the length of the bed from the headboard to the footboard change the way the mattress lies from top to bottom, and cross rails added across the bed frame change the way the mattress lies from side to side.
  
  

Installing Side Shims or Cross Rails

• To create shims to lift the sides of the mattress to angle the mattress from the headboard to the footboard, cut two pieces of wood to the same length as the bedrails. Sand the wood pieces down to a slope to compensate for the headboard-to-footboard slope in the mattress caused by the uneven floor. Cut several pieces of wood to the width of the bed and sand them into a slope to compensate for a side-to-side slope in the mattress.
  
  

Build Up Floor

• The most secure way to even up a bed on an uneven floor is to fix the floor surface instead of the bed. Level dips in concrete or wood floor surfaces with leveling compound. While the process is simpler on unfinished floors than on covered floors, any floor may be leveled by removing the carpet or tile floor covering and leveling the concrete or wood subfloor beneath. This is a more complicated process than adjusting the bed, but provides a permanent fix.