Box springs give a bed height, but not everyone feels the need to use a step stool to climb into bed every night. An injury or illness may also necessitate the a lower bed. Without the box spring to support it, a mattress would slip through the bed frame. Converting a box spring bed frame to a slat frame is a simple process that does not require any special skills. It is even possible to salvage the wood from the unwanted box spring to use as building materials for the slat frame.
Remove the mattress and box spring from the bed frame. If your frame is metal, check to make sure that it is secure at all of its connection points by turning the screws as tightly as possible. Measure the interior dimensions of the frame (length and width).
Calculate how many individual slats you will need. Divide the length of your bed frame into 6-inch segments. For every 6 inches of length, 4 will be filled with one of the slats and the remaining 2 will be fitted with a small block. This block is put in place to keep the slats from moving once the mattress is in place.
Measure and cut the slats to length with a circular saw. The exact length of the slats will depend on the size of the bed. To ensure a tight fit, make sure that the measurement you are using extends to the interior edge of the bed frame and not only to the lip that the box spring rested on.
Cut blocks from the remaining 2X4 lumber that measure 2 inches wide. Mark 6-inch segments on the bed frame along both sides. Glue one of the blocks to the frame at the end of each segment.
Lay the slats down in the remaining gaps. The slats do not need to be secured in any way since the blocks will keep them from sliding and pressure from the mattress will keep them in place. Put the mattress back onto the bed frame and discard the box spring.
Since box spring frames are constructed out of lumber, when converting a twin bed from box spring to slats you can salvage wood from the box spring to construct the slats and save yourself a trip to the lumber store. Remove the blocks and place the slats closer together (nearly touching) if you prefer a more solid base.